Thursday, September 4, 2008

Emperor Ai of Tang

Emperor Tang Aidi , born Li Zhu, was the last emperor of the Tang dynasty of China. He reigned from 904 to 907. Aidi was the son of .

Aidi ascended the throne at the age of 13 after his father, the Zhaozong was murdered by Zhu Wen in 904. Under Zhu Wen's regency, Aidi was only a puppet emperor. In 905, seeing the timing was ripe, Zhu Wen forced Aidi to issue an edict and ordered the execution of all remaining handful of ministers still loyal to the imperial Li family. The ministers were brought to a river and summarily executed after which their bodies were thrown into the river. Less than two years later, Zhu made his final move against Aidi himself and the emperor was forced to abdicate and demoted to Ji Yin Wang whilst Zhu Wen proclaimed the Later Liang Dynasty thus ending 290 years of rule by the Tang dynasty.

In 908, Aidi was poisoned to death by Zhu Wen. He was only 17.

Emperor Xizong of Tang

Emperor Tang Xizong , born Li Xuan, was the 18th emperor of the Tang dynasty of China. He reigned from 873 to 888. Xizong was the fifth son of emperor and elder brother of emperor .

Xizong's reign was dominated by eunuchs and governmental affairs was delegated to corrupt officials such as Tian Lingmu while Xizong totally ignored his duties. Ordinary citizens suffered under the heavy burden of taxes while famines caused by natural disaster became widespread across the country. In 874, the Wang Xianzhi rebellion broke out followed in 875 by the infamous Huang Chao rebellion that would haunt Xizong's reign for the next decade. In 880, the Huang Chao rebellion even captured the imperial capital of Chang'an and Xizong quickly fled to Sichuan. Both rebellions would ultimately be suppressed however it would cost the Tang dynasty dearly and hasten its downfall.

Xizong died in 888 after reigning for 15 years. He was only 27.

Emperor Daizong of Tang

Emperor Tang Daizong 唐代宗李豫 , born Li Chu ; in 758 he renamed himself Li Yu . He was the eighth emperor of the Tang dynasty and reigned from the fifth month of 762 to the fifth month of 779. He was the son of Emperor Suzong. During the An Lushan Rebellion, he acted as a general and was the representative of the royal family at the two capitals . At the beginning of his reign, general prefect-king of Fenyang Guo Ziyi successfully quelled the Anshi Rebellion, which had plagued the dynasty for over seven years. In 763, while both Daizong and Guo were in Luoyang, Tibetan forces suddenly occupied the capital of Chang'an. The Tibetan forces were, however, defeated within a few days.

Other notable events during Daizong's reign included a plot by a corrupt eunuch named Li Fuguo to gain control of the administration by murdering Daizong's stepmother. Li subsequently tried to confine Daizong to the palace while he controlled affairs of state. Daizong realized Li's motives and had Li assassinated along with numerous other corrupt eunuchs. Daizong was a devout and spent huge sums of money on building temples and shrines. Later this would prove to be a financial burden for the empire and hastened the decline of the dynasty.

Emperor Dezong of Tang

Emperor Tang Dezong , born Li Kuo, was the 9th emperor of the Tang dynasty of China. He reigned from 779 to 805. Dezong was the eldest son of emperor Emperor Daizong of Tang.

Created crown prince in 764, Dezong ascended the throne in the sixth month of 779. Dezong's long reign was one of stability during the middle period of the Tang dynasty. He was a diligent and frugal emperor and he tried to reform the governmental finances by introducing new tax laws. With his minister, Yang Yan, Dezong implemented some of the most sweeping reforms of China's bureaucracy and taxation in decades, but prompted clashes with the aristocracy.

In addition, Dezong realized the importance to limit the strength of the Fanzhen 藩镇, a situation where regional military governors or Jiedushi have sprung up after the An Lushan rebellion, to take control of huge border areas of the empire. These fiefs were a direct challenge to the central administration of the Tang empire but when Dezong's attempted to limit its power, these fiefs revolted and Dezong was forced to flee the capital of Chang An. As a result, Dezong eventually decreed that he would not limit their power. Dezong's inability to control the Fanzhen weakened the centralized power of the Tang dynasty and would contribute to a series of rebellions in the middle of the 9th century and ultimately lead to its downfall early in the 10th century.

Dezong died in the first month of 805 in the Daming Palace at the age of 63 after reigning for almost 26 years. He was succeeded by his son.

Emperor Shunzong of Tang

Emperor Tang Shunzong , born Li Song, was the tenth emperor of the Tang dynasty of China. He was created crown prince in 779 and reigned in 805 and lasted less than a year . Shunzong was the eldest son of emperor Emperor Dezong of Tang.

Shunzong was a hardworking and diligent emperor and he employed capable individuals such as Liu Zongyuan, Liu Shunchi, Han Tai, Han Hua as well as many others who supported Shunzong in reforming and rejuvenating the administration. Shunzong also tried to subdue the powers of corrupt eunuchs and its initial result, albeit shortlived, was quite successful thus earning Shunzong's short reign Era of the Yong Zhen Reformation . It gave the Tang dynasty brief stability but in August of 805, Shunzong fell ill after a stroke and was forced by corrupt officials to abdicate in favour of his son.

Shunzong died in the first month of the next year in the Xingqing Palace. It was rumoured he was murdered by corrupt officials. He was 46.

Emperor Xianzong of Tang

Emperor Tang Xianzong , born Li Chun, was the 11th emperor of the Tang dynasty of China. He reigned from 805 to 820. Xianzong was the eldest son of emperor Shunzong. He was created crown prince in 805 after the ascension of his father emperor Shunzong but was forced to abdicate within a year by corrupt eunuchs. In August of 805, Xianzong was quickly replaced as emperor.

Xianzong realized the growing threat of the Fanzhen and was determined to rid the empire of all them by waging battles against them. His initial campaigns were quite successful and Xianzong's army defeated Jiedushi such as Liu Peng, Yang Huilin in 806 and in 807. In 813, military governor Tian Xing quickly surrendered to the Tang army. Xianzong's first set back was in 813 when he failed to defeat military governor Wang Chenzong. However by 817, almost all the regional military governors have agreed in principal to submit to the Tang dynasty.

Xianzong's reign briefly stabilized the Tang dynasty from the destructive forces of the military governors however by the middle of the 9th century, unattentive emperors controlled by corrupt eunuchs gradually weakened the centralized power of the Tang dynasty. During his reign, Xianzong even bestowed military authorities to eunuchs which set the stage for eunuchs to gain power and the ability to arbitrary remove and murder any emperor they do not like. Xianzong himself was allegedly murdered by the eunuch Chen Hongzheng in the first month of 820. He was 42.

Emperor Muzong of Tang

Emperor Tang Muzong , born Li Heng, was the 12th emperor of the Tang dynasty of China. He reigned from 820 to 824. Muzong was the son of emperor Xianzong. He was created crown prince in 812 during the reign of his father but after his father was allegedly poisoned by corrupt officials, Muzong was proclaimed emperor in the firsth month of 820.

After succeeding the throne, Muzong spent his time throwing parties and heavy drinking thereby neglected his duties as emperor. Meanwhile, the temporarily subdued regional military governors began to start challenging the central Tang government. Internally, corruptions was rife however Muzong all but ignored the situation.

Muzong brief reign came to an end in the first month of 824. He was only thirty. His reign would mark the downward spiral of the Tang dynasty.

Emperor Jingzong of Tang

Emperor Tang Jingzong , born Li Zhan, was the 13th emperor of the Tang dynasty of China. He reigned from 824 to 826. Jingzong was the eldest son of emperor and elder brother of emperor .

Emperor Jingzong became emperor an early age of 15 and his short reign would be overshadowed by corrupt military eunuchs that would come to dominate his rule as well as his younger brother who eventually became emperor Wenzong. Uninterested in ruling, Jingzong gave into pleasure seeking and lived in opulence while eunuchs such as Wang Shouchen and officials such as Li Fengji held onto real power.

In twelfth month of 827, after reigning less than 4 years, emperor Jingzong was murdered by another corrupt eunuch named Liu Keming and was succeeded by his younger brother. Jingzong was only 18 when he died.

Emperor Wenzong of Tang

Emperor Tang Wenzong , born Li Ang, was the 14th emperor of the Tang dynasty of China. He reigned from 826 to 840. Wenzong was the second son of emperor and younger brother of emperor .


Emperor Wenzong ascended the throne after his elder brother, Emperor Jingzong was murdered by the corrupt eunuch Wang Shoucheng after reigning less than four years. Ever since the An Lushan rebellion in the middle of the eighth century, corrupt eunuchs had held sway over the government. Wenzong's tenure was plagued with political infighting between eunuch factions and ministers loyal to the emperor. Aided by officials such as Li Xun and Zheng Ju, Wenzong attempted to remove all corrupt eunuchs from power. This resulted in a plot hatched by Li Xun to ambush and kill all the corrupt eunuchs while they were invited to a gathering one day in 835. The plot was finally discovered and Wenzong was held hostage and put under house arrest while Li Xun and Zheng Ju was executed.

Wenzong died in the first month of 840 after five years of house arrest and reigning for 13 years and one month perhaps lamenting the fact that he was an emperor but was controlled by his servants. He was succeeded by his younger brother.


Emperor Wenzong issued an imperial decree, stating 's , Pei Min's swordplay and Li Bai's poetry as the "Three Wonders of the Great Tang Empire".

Emperor Wuzong of Tang

Emperor Tang Wuzong , born Li Yan, was the fifteenth emperor of the Tang dynasty of China, reigning from 840 to 846. Wuzong is remembered mainly for the religious persecution that occurred during his reign.

Wuzong ascended to the throne in a time of economic and political crisis. Military had controlled the government for some time. They had put the previous emperor, Wuzong's older brother , under house arrest, where he apparently drank himself to death. The eunuchs had also murdered the last two emperors before him, and . Meanwhile, the Khanate was attacking China from the northwest. Imperial finances were in trouble as most provinces were not paying any taxes to the central government. With the help of his uncle, the future , Wuzong was able to stage a coup against the eunuchs and ascend to the throne. He and his prime minister Li Deyu were able to curb the eunuchs' power. Li Deyu took personal command of the war against the Uyghurs and won an important victory in 843.

Wuzong's solution to the financial crisis was to seize the property of Buddhist monasteries. Buddhism had flourished into a major religious force in China during the Tang period, and its monasteries enjoyed tax-exempt status. He closed many Buddhist shrines, confiscated their property, and sent the monks and nuns home to lay life. However, Wuzong's reasons for doing so were not purely economic. A zealous Taoist, Wuzong considered Buddhism a foreign religion that was harmful to Chinese society. He went after other foreign religions as well. He all but destroyed Zoroastrianism and Manichaeism in China, and his persecution of the growing churches sent Chinese Christianity into a decline from which it never recovered. At the same time, Wuzong went far to promote Taoist worship in China through religious regulations and the construction of the Temple for Viewing Immortals in the Imperial court.

Tang Wuzong was one of the last Tang emperors and ruled China during a long period of decline; despite his reforms, he was unable to revive the empire through his religious persecutions. After his death, with the help of his son Wenzong, Buddhism was able to recover from the persecution; but Christianity, Manichaeism, and Zoroastrianism, however, never again played as significant a role in Chinese religious life.

Emperor Yizong of Tang

Emperor Tang Yizong , born Li Cui, was the 17th emperor of the Tang dynasty of China. He reigned from 859 to 873. Yizong was the eldest son of emperor .

After the death of emperor Xuanzong in 859, Yizong was placed on the throne by powerful corrupt eunuchs and officials. Yizong was a lazy emperor and did not pay much attention to governmental affairs but instead chose to live in opulence, became an alcoholic and surrounded himself with women while his government levied heavy taxes on its citizens. Yizong even exhausted the empire's treasury that had accumulated during his father's administration. Faced with insurmountable hardship, with stories of cannibalism due to starvation and famines, rebellions broke out throughout the country in 859 that would ravage China for the next 25 years. Although a successive series of rebellions broke out throughout the country, Emperor Yizong never did anything to remedy the situation. His reign marked the beginning of the end of the Tang dynasty.

Yizong died in 873 after reigning for 14 years. He was succeeded by his son.

Emperor Zhaozong of Tang

Emperor Tang Zhaozong , born Li Ye, was the 19th emperor of the Tang dynasty of China. He reigned from 889 to 904. Zhaozong was the seventh son of Emperor Yizong of Tang and younger brother of emperor Emperor Xizong of Tang.

During Zhaozong's reign, the Tang dynasty fell into disarray and rebellions broke out throughout the country. Ever since rebellions broke out in 859, a series of successive rebellions followed and the Tang dynasty endured over 25 years of non-stop violence ending with the Huang Chao rebellion in 884 when Zhu Wen sided with the Tang. By Zhaozong's reign, the Tang dynasty existed all but in name. Corruption and civil unrest paralyzed the government and Zhu Wen saw the opportunity to take control of the empire by murdering Zhaozong in 904. Zhu Wen replaced Zhaozong's 13 year old son as a puppet emperor whilst Zhu Wen became the de facto ruler.

Zhaozong's reign lasted almost 16 years and he was buried in He Ling.

Emperor Gaozu of Tang

Emperor Gāozǔ of Táng , born Lǐ Yuān , was the founder of the Tang Dynasty of China, and the first emperor of this dynasty from 618 to 626. Under the Sui dynasty, Li Yuan was the governor in the area of modern-day Shanxi, and was based in Taiyuan.

In 615, Li Yuan was assigned to garrison Longxi. He gained much experience by dealing with the G& of the north and was able to pacify them. Li Yuan was also able to gather support from these successes and, with the disintegration of the Sui dynasty in July of 617, Li Yuan - urged on by his second son - rose in rebellion. Using the title of "Great Chancellor" , Li Yuan installed a puppet child emperor, , but eventually removed him altogether and established the Tang Dynasty in 618 as Emperor Gaozu .

Emperor Gaozu's reign was concentrated on uniting the empire under the Tang. Aided by Li Shimin , whom he created the Prince of Qin, he defeated all the other contenders, including Li Gui, Dou Jiande, Wang Shichong, Xue Rengao and Liu Wuzhou. By 628, the Tang Dynasty had succeeded in uniting all of China. On the home front, he recognized the early successes forged by Emperor Wen of Sui and strove to emulate most of Emperor Wen's policies, including the equal distribution of land amongst his people, and he also lowered taxes. He abandoned the harsh system of law established by Emperor Yang of Sui as well as reforming the judicial system. These acts of reform paved the way for the reign of Emperor Taizong, which ultimately pushed Tang to the height of its power.

In 626, Li Shimin, in a dispute with his brothers Li Jiancheng the Crown Prince and Li Yuanji the Prince of Qi, ambushed Li Jiancheng and Li Yuanji at , killing them. Fearful of what Li Shimin might do next, Emperor Gaozu passed the throne to him and became ''Taishang Huang'' . He died in 635.

Background and early career

Li Yuan's seventh-generation ancestor was Li Gao, the founder of the Sixteen Kingdoms state Western Liang. After Western Liang's destruction, Li Gao's grandson Li Chong'er served as a Northern Wei official, but for several generations after that, Li Yuan's ancestors had only minor military titles. Li Yuan's grandfather Li Hu served as a major general under Western Wei's paramount general Yuwen Tai, and was created the Duke of Longxi and given the Xianbei surname Daye . Li Hu died before Yuwen Tai's son Emperor Xiaomin of Northern Zhou founded Northern Zhou, but was posthumously created the Duke of Tang after Northern Zhou's founding. His son and Li Yuan's father Li Bing inherited the title of the Duke of Tang and married a daughter of the prominent general Dugu Xin . Li Bing died in 572, and Li Yuan inherited the title of Duke of Tang, a title he continued to hold after the throne was seized by Emperor Wen of Sui in 581, establishing Sui Dynasty, as Emperor Wen's wife, Empress Dugu Qieluo, was an aunt of his. At some point, he married Lady Dou, a daughter of Dou Yi the Duke of Shenwu and Northern Zhou's Princess Xiangyang as his wife and duchess.

During Emperor Wen's reign , Li Yuan served three terms as provincial governors. Early in the reign of Emperor Wen's son , Li Yuan served as commandery governors , but was later recalled to serve as a junior minister within Emperor Yang's administration. When Emperor Yang carried out his second campaign against Goguryeo in 613, Li Yuan was in charge of part of the logistics operation, when the general Yang Xuangan rebelled near the eastern capital Luoyang. Emperor Yang commissioned Li Yuan as a general and made him be in charge of the operations west of the Tong Pass, although Yang Xuangan's rebellion eventually did not involve that region. Li Yuan took the opportunity to recruit talented people to his staff. Later that year, when Emperor Yang summoned him, he declined based on the reason of illness -- a reason that Emperor Yang did not believe, as he questioned Li Yuan's niece, a Consort Wang , "Will he die?" In fear, Li Yuan took up drinking and receiving bribes to try to show Emperor Yang that he did not have great ambitions. In 615, Emperor Yang made him in charge of the operations against agrarian rebels in the Hedong region , but recalled him in 616. Later that year, Emperor Yang put him in charge of the key city of Taiyuan .

Rebellion against Emperor Yang of Sui

Emperor Yang was soon dissatisfied with Li Yuan and Wang Rengong , the governor of Mayi Commandery , over their inability to stop Eastern Tujue incursions and the growing strengths of agrarian rebels, particularly the Eastern Tujue-support Liu Wuzhou the Dingyang Khan, who soon rose against Wang and killed him and soon captured Emperor Yang's secondary palace near Taiyuan. Li Yuan also became fearful that there had been prophecies throughout the empire that the next emperor would be named Li -- and that Emperor Yang had killed another official, Li Hun and Li Hun's clan over his fears that Li Hun's nephew Li Min had imperial ambitions.

Meanwhile, Li Yuan's second son, by his wife Duchess Dou , , was with him in Taiyuan, and was secretly planning rebellion against Sui rule with Pei Ji the head of the household at Emperor Yang's secondary palace nearby and Liu Wenjing the Jinyang County magistrate, but at first did not reveal their plans to Li Yuan. At Li Shimin's urging, Pei Ji, who had also earlier, against regulations, allowed Li Yuan to have sexual relations with some of Emperor Yang's , persuaded Li Yuan that it was necessary for him to rebel. Li Yuan began to gather forces from the region, claiming that they were necessary to defend against Eastern Tujue, which drew suspicions from his deputies Wang Wei and Gao Junya . Li Yuan, also fearful that Wang and Gao would act against him first, then used an Eastern Tujue attack as an excuse to falsely claim that Wang and Gao were working in concert with Eastern Tujue's Shibi Khan Ashina Duojishi, executing them, while preparing for formal declaration of rebellion. He sent secret messengers to Hedong to recall his sons and the capital Chang'an to recall his daughter and her husband Chai Shao . Li Jiancheng and Li Yuanji, leaving Li Zhiyun at Hedong, soon met with Chai, and they togethered arrived at Taiyuan.

Once Li Jiancheng, Li Yuanji, and Chai arrived at Taiyuan, Li Yuan formally declared his rebellion -- but cast it as a declaration of his wishes to declare Emperor Yang's grandson the Prince of Dai, who was then at Chang'an, emperor, and honor Emperor Yang as ''Taishang Huang'' . He contacted Ashina Doujishi, offering tributes, and received logistical support from Eastern Tujue. He put Li Jiancheng and Li Shimin in charge of his army and, leaving Li Yuanji in charge at Taiyuan, advanced south.

Meanwhile, Li Yuan wrote another rebel leader, Li Mi the Duke of Wei, who was near Luoyang, trying to see if Li Mi would be willing to follow him, but Li Mi, believing in his own strength, had his secretary Zu Junyan write Li Yuan for him in this way:

:''Although I and you, my older brother, are of different branches, but we are both Lis. I know that I do not have sufficient strength, but by the love of the men on this earth, I have been made the leader. I hope that you will support and help me. Let us capture Ziying at Xianyang, and let us kill at Muye; would it not be a great accomplishment?''

Li Yuan was dismayed but, not wanting to make another enemy, wrote back humbly:

:''Although I am ordinary and foolish, but I have had the opportunity to, by my ancestors' largess, receive the opportunity to be an imperial messenger when leaving the capital and a guard leader in the capital. If the administration falls and I am unable to help it, even the most understanding wise man will rebuke me. Therefore, I have organized a righteous army and sought peace with the barbarians to the north to try to calm the earth and to protect Sui. However, for the people under the heavens, there must be someone to rule over them, and other than you, who can be that person? I am too old -- over 50 -- and that is not my intent, but I am happy to support you, my younger brother. I hope to be able to climb onto the scale of a dragon and hold onto the wing of a phoenix, and I hope that you, my younger brother, will soon, in accordance with the prophecy, pacify all who are on this earth. You are the leader among the Li, and I hope that you will be gracious and accept me, and to give me again the domain of Tang; that will be enough glory for me. I do not have the heart to hear such commands as killing Xin of Shang at Muye, nor do I dare to listen to the order of capturing Ziying at Xianyang. Also, the Fen and Jin region requires pacification right now, and I am not yet able to arrange a time for the meeting at Mengjin .''

Li Mi was pleased with Li Yuan's response, believing that Li Yuan was willing to support him, and from that point on, Li Mi and Li Yuan often exchanged messengers. Li Yuan's campaign against Chang'an thus went without opposition from Li Mi. Meanwhile, however, when Li Yuan arrived near Hedong, his army was bogged down by the weather, and with food running out, there were rumors that Eastern Tujue and Liu Wuzhou would attack Taiyuan. Li Yuan initially ordered retreat, but at the earnest opposition by Li Jiancheng and Li Shimin, continued to advance. After defeating Sui forces at Huoyi , he decided to leave a small contingent to watch over Hedong while advancing across the Yellow River into Guanzhong . Once he did, he headed for Chang'an himself, while sending Li Jiancheng to capture the territory around the Tong Pass region to prevent Sui forces at Luoyang from reinforcing Chang'an and Li Shimin north of the Wei River to capture territory there. Meanwhile, his daughter had also risen in rebellion in support of him, and she was able to gather a sizable army and capture some cities. She joined forces with Li Shimin and her husband Chai Shao. Soon, Li Yuan reconsolidated his forces and put Chang'an under siege. In winter 617, he captured Chang'an and declared Yang You emperor . He had himself made regent and created the Prince of Tang. He sent his nephew Li Xiaogong south, and Li Xiaogong was able to persuade the Sui cities in modern southern Shaanxi, Sichuan, and Chongqing to submit.

Establishment of Tang and gradual unification

In spring 618, Emperor Yang was killed at Jiangdu in a coup led by the general Yuwen Huaji. When the news reached Chang'an, Li Yuan had Emperor Gong yield the throne to him, establishing Tang Dynasty as its Emperor Gaozu. He restored much of the institutions of Sui's Emperor Wen, reversing a number of changes that Emperor Yang made. He created Emperor Gong the Duke of Xi, and created Li Jiancheng, as his oldest son, crown prince, while creating Li Shimin the Prince of Qin and Li Yuanji the Prince of Qi. Meanwhile, the Sui officials at Luoyang declared another grandson of Emperor Yang, Emperor Gong's brother Yang Tong the Prince of Yue, as emperor, and refused to recognize the regime change in Chang'an.

Emperor Gaozu's rule immediately faced a major challenge from Xue Ju, an agrarian leader who had declared himself the Emperor of Qin, as Xue, during the fall of 618, took advantage of Li Shimin's illness to defeat an army commanded by Li Shimin and Liu Wenjing at Qianshui Plain and approach Chang'an. Emperor Gaozu, in response, tried to enter an alliance with Li Gui the Prince of Liang, between whose domain and the Tang was Xue's Qin state, writing Li Gui and referring to him as cousin. Li Gui briefly submitted to Emperor Gaozu. Meanwhile, before he could attack Chang'an, Xue Ju died of illness and was succeeded by his son Xue Rengao, who was a capable commander but who had alienated his generals because of his cruelty. Li Shimin was soon able to attack Xue Rengao at Gaozhi , and force Xue Rengao to surrender.

Meanwhile, Li Mi, having been defeated earlier in the year in a surprise attack by the Sui general Wang Shichong, fled to Tang territory and submitted to Emperor Gaozu. Li Mi's general , who controlled a major part of Li Mi's former territory, also submitted, and Emperor Gaozu, impressed with Xu's faithfulness to Li Mi, bestowed the imperial surname of Li on Xu. Emperor Gaozu created Li Mi the Duke of Xing, but only made him the Minister of Feasts, a post that Li Mi viewed as below his stature. Around the new year 619, Li Mi requested Emperor Gaozu's permission to head east to persuade some of his former subordinates to submit to Tang, and once he left Chang'an, planned to restore his independence. He was ambushed and killed by the Tang general Sheng Yanshi .

In spring 619, Wang had Yang Tong yield the throne to him, ending Sui and establishing a new state of Zheng.

Around the same time, Li Gui, while stating that he wished to be a Tang subject, refused the Tang creation of Prince of Liang, instead declaring himself the Emperor of Tang. Emperor Gaozu broke off his relations with Li Gui. In summer 619, Li Gui's official An Xinggui , formerly a Tang official, rebelled against Li Gui and captured him, submitting to Tang. Emperor Gaozu executed Li Gui and incorporated his domain into Tang. Also around the same time, the rebel leader Du Fuwei, who controlled the modern southern Anhui, submitted to Tang, and Emperor Gaozu also bestowed the imperial surname of Li on him, creating him the Prince of Wu. Similarly, Luo Yi, who controlled the modern Beijing region, submitted, was bestowed the imperial surname of Li, and was created the Prince of Yan.

Meanwhile, Tang was facing another serious threat -- Liu Wuzhou, now determined to march south against Tang. Emperor Gaozu sent Pei Ji against Liu's advancing army, but Pei was defeated by Liu, who then put Taiyuan under siege. Li Yuanji fled back to Chang'an, and much of modern Shanxi was seized by Liu. Emperor Gaozu then sent Li Shimin against Liu, and by summer 620, Li Shimin had defeated Liu, forcing him to flee to Eastern Tujue. Liu's territory was incorporated into Tang. Around the same time, however, Dou Jiande the Prince of Xia made a major offensive against the cities that had submitted to Tang in modern Hebei and Henan, north of the Yellow River, seizing nearly all of them and taking Emperor Gaozu's cousin Li Shentong the Prince of Huai'an, Emperor Gaozu's sister the Princess Tong'an, and Li Shiji's father Li Gai captive. With Li Gai in Dou's custody, Li Shiji surrendered to Dou as well. In 620, Li Shiji, in association with another Tang general who surrendered to Dou, Li Shanghu , plotted to ambush Dou, but the plot was discovered; Li Shanghu was killed, and Li Shiji fled back to Tang.

In 620, Li Fuwei captured much of the territory of another agrarian ruler, Li Zitong the Emperor of Wu, in the lower Yangtze River region, in the name of Tang Dynasty. Li Zitong, in turn, defeated and took over the territory of Shen Faxing the Prince of Liang, roughly modern Zhejiang.

After Li Shiimin defeated Liu, he started a campaign against Wang's Zheng state in fall 620. He initially could not decisively defeat Zheng, but by spring 621 had put the Zheng capital Luoyang under a tight siege, although he was not able to capture it. Wang sought aid from Dou, and Dou, believing that if Zheng were destroyed, his Xia state would be cornered, agreed to render aid. Emperor Gaozu was initially fearful that Dou and Wang would be able to sandwich Li Shimin's forces and ordered Li Shimin to retreat, but upon Li Shimin's petition changed his mind and permitted Li Shimin to remain in the Luoyang region. Li Shimin, leaving Li Yuanji in charge of the siege of Luoyang, advanced and took up position at Hulao Pass. In summer 621, the Tang and Xia forces engaged at Hulao, and Li Shimin defeated Dou, capturing him. In fear, Wang also surrendered. Most of Zheng territory was seized by Tang. Xia territory was also seized by Tang, but after Emperor Gaozu executed Dou, Dou's general Liu Heita rose against Tang, seizing most of former Xia territory, while Xu Yuanlang, a rebel leader who had previously submitted to Zheng, also rose, occupying the modern Shandong region.

Also in 621, Li Xiaogong defeated Xiao Xi the Emperor of Liang, who had controlled the modern Hubei, Hunan, and Guangxi region, forcing Xiao Xi to surrender. On another front, Li Fuwei's lieutenant Fu Gongshi defeated Li Zitong, forcing him to surrender as well. Liang and Wu territory were seized by Tang.

Meanwhile, while not noted as Emperor Gao of Han's killing of Han Xin and Peng Yue, the historians had nevertheless noted that some contributors to Emperor Gaozu's establishment of Tang were wrongly killed by him or killed based on fairly little evidence of wrongdoing:
* Liu Wenjing, in 619, on accusation that he engaged sorcerers.
* Emperor Gaozu's cousin Dugu Huai'en , in 620, on accusation of treason.
* Li Zhongwen the Duke of Zhenxiang, in 620, on accusation of collaboration with Eastern Tujue.
* Liu Shirang the Duke of Yingyang, in 623, on accusation of collaboration with Eastern Tujue.

Struggle between sons and the Incident at Xuanwu Gate

In spring 622, Li Shimin defeated Liu Heita, forcing him to flee to Eastern Tujue, but Liu Heita soon returned with Eastern Tujue reinforcements and killed Emperor Gaozu's nephew Li Daoxuan the Prince of Huaiyang in battle, again seizing former Xia territory, although by this point Li Shimin and Li Yuanji had also defeated Xu Yuanlang and reduced his territory to a few cities.

Meanwhile, an intense rivalry had developed between Li Jiancheng and Li Shimin, as while Li Jiancheng had some contributions toward Tang's reunification of China, Li Shimin had been the one defeating and capturing the major rivals Xue Rengao, Liu Wuzhou, Dou Jiande, and Wang Shichong, causing him to possess the greater reputation among the army. Li Yuanji, who was also often relied on by Emperor Gaozu as a general, supported Li Jiancheng in this rivalry, and often pushed Li Jiancheng toward a more hardline position against Li Shimin, wanting to be crown prince when Li Jiancheng would become emperor. Li Jiancheng and Li Yuanji had better relations with Emperor Gaozu's favored young concubines than Li Shimin did , and those concubines helped rehabilitate Li Jiancheng's standing before Emperor Gaozu, causing him to no longer consider making Li Shimin crown prince instead, as he considered at one point.

By winter 622, Liu Heita posed the only remaining major threat against Tang rule. At the suggestion of his staff members Wang Gui and Wei Zheng, who argued that Li Jiancheng needed some victories himself to establish his reputation, Li Jiancheng volunteered to command the army against Liu Heita. Emperor Gaozu thus sent Li Jiancheng, assisted by Li Yuanji. Around the new year 623, with Liu's forced bogged down while attacking Tang's Wei Prefecture , Li Jiancheng and Li Yuanji engaged him at Guantao , crushing him. Liu fled north toward Eastern Tujue, but was ambushed and captured by his own official Zhuge Dewei , who delivered him to Li Jiancheng. Li Jiancheng executed Liu. Around the same time, Xu was killed in flight. Meanwhile, Lin Shihong the Emperor of Chu, who had one point controlled modern Jiangxi and Guangdong, had died, and his followers scattered. China was by this point completely unified by Tang except for the domain of Liang Shidu the Emperor of Liang, who controlled modern northern Shaanxi and western Inner Mongolia, although, with Li Fuwei at Chang'an, Fu Gongshi rebelled in 623 and declared himself the Emperor of Song. Fu's rebellion, however, was quelled by Li Xiaogong in 624.

Meanwhile, the rivalry between Li Jiancheng and Li Shimin intensified. In 624, Li Jiancheng requisitioned a number of soldiers from the general the Prince of Yan, to supplement his guard corps, against Emperor Gaozu's regulations. When this was revealed to Emperor Gaozu, Emperor Gaozu rebuked Li Jiancheng and exiled his guard commander Keda Zhi . When, subsequently, Li Jiancheng nevertheless requested the commandant at Qing Prefecture , Yang Wen'gan , to conscript troops, presumably to guard against Li Shimin, the officers Erzhu Huan and Qiao Gongshan informed Emperor Gaozu that Li Jiancheng was encouraging Yang to start a rebellion so that they could seize power together. Emperor Gaozu, then at Renzhi Palace , was incensed, and summoned Li Jiancheng, then at Chang'an, to Renzhi Palace. Li Jiancheng briefly flirted the idea of occupying Chang'an and not accepting the order, but eventually reported to Renzhi Palace to request forgiveness. Emperor Gaozu put him under arrest. When Yang heard this, Yang rebelled, and Emperor Gaozu, after promising Li Shimin that he would be made crown prince, sent Li Shimin to attack Yang. Once Li Shimin left, however, Li Yuanji, Emperor Gaozu's concubines, and the chancellor Feng Deyi, all spoke on Li Jiancheng's behalf, and Emperor Gaozu changed his mind, released Li Jiancheng, and allowed him to return to Chang'an and remain as crown prince. Instead, Emperor Gaozu only blamed the discord between his sons on Li Jiancheng's staff members Wang Gui and Wei Ting , and Li Shimin's staff member Du Yan, exiling them. Yang was subsequently assassinated by his own subordinates.

Another problem that Emperor Gaozu faced was constant Eastern Tujue incursions. Emperor Gaozu seriously considered burning Chang'an to the ground and moving the capital to Fancheng , a suggestion that Li Jiancheng, Li Yuanji, and the chancellor Pei Ji agreed with. Li Shimin opposed, however, and the plan was not carried out. Meanwhile, Li Shimin himself was sending his confidants to Luoyang to build up personal control of the army there. After an incident in which Li Shimin suffered a severe case of food poisoning after feasting at Li Jiancheng's palace -- an event that both Emperor Gaozu and Li Shimin apparently interpreted as an assassination attempt -- Emperor Gaozu considered sending Li Shimin to guard Luoyang to prevent further conflict, but Li Jiancheng and Li Yuanji, after consulting each other, believed that this would only give Li Shimin an opportunity to build up his personal power there, and therefore opposed it. Emperor Gaozu therefore did not carry out the plan.

By 626, Li Shimin was fearful that he would be killed by Li Jiancheng, and his staff members Fang Xuanling, Du Ruhui, and Zhangsun Wuji were repeatedly encouraging Li Shimin to attack Li Jiancheng and Li Yuanji first -- while Wei Zheng was encouraging Li Jiancheng to attack Li Shimin first. Li Jiancheng persuaded Emperor Gaozu to remove Fang and Du, as well as Li Shimin's trusted guard officers Yuchi Jingde and Cheng Zhijie , from Li Shimin's staff. Zhangsun, who remained on Li Shimin's staff, continued to try to persuade Li Shimin to attack first.

In summer 626, Eastern Tujue was making another attack, and under Li Jiancheng's suggestion, Emperor Gaozu, instead of sending Li Shimin to resist Eastern Tujue as he first was inclined, decided to send Li Yuanji instead. Li Yuanji was given command of much of the army previously under Li Shimin's control, further troubling Li Shimin, who believed that with the army in Li Yuanji's hands, he would be unable to resist an attack. Li Shimin had Yuchi summon Fang and Du back to his mansion secretly, and then on one night submitted an accusation to Emperor Gaozu that Li Jiancheng and Li Yuanji were committing adultery with Emperor Gaozu's concubines. Emperor Gaozu, in response, issued summonses to Li Jiancheng and Li Yuanji for the next morning, convening the senior officials Pei Ji, Xiao Yu, and Chen Shuda to examine Li Shimin's accusations. As Li Jiancheng and Li Yuanji approached the central gate leading to Emperor Gaozu's palace, Xuanwu Gate , Li Shimin carried out the ambush he had set. He personally fired an arrow that killed Li Jiancheng. Subsequently, Yuchi killed Li Yuanji. Li Shimin's forces entered the palace and, under the intimidation of Li Shimin's forces, Emperor Gaozu agreed to create Li Shimin crown prince, and two months later passed the throne to him . Li Jiancheng's and Li Yuanji's sons were all executed as well, with Emperor Gaozu not daring to oppose the action.

As retired emperor

Emperor Gaozu, as retired emperor, did not appear to try to exert much influence in the reign of his son Emperor Taizong, and not much was recorded about his activities. Indeed, Emperor Taizong, almost immediately, began reversing some of his policies, including his policies of creating many relatives to be imperial princes and Emperor Gaozu's gathering of many ladies in waiting .

In 629, Emperor Gaozu moved from the main palace, Taiji Palace to the subsidiary Honyi Palace , which was then renamed Da'an Palace . Only then was Emperor Taizong able to move from the crown prince's palace to Taiji Palace.

In 630, when Emperor Gaozu, who had been submitting tributes to Eastern Tujue throughout his reign, heard that Emperor Taizong had sent the general Li Jing to defeat and capture Eastern Tujue's Jiali Khan Ashina Duobi, commented, "Gaozu of Han was trapped at Baideng and could not avenge himself. Now my son can destroy Tujue. I have entrusted the empire to the right person, and what do I have to worry about?" He subsequently summoned a number of princes and princesses, along with high level officials, to celebrate the victory, playing the pipa himself at the celebration and having the guests dance to it.

As Chang'an was often hot during the summer, Emperor Taizong often invited Emperor Gaozu to go with him to Jiucheng Palace , to avoid the heat during the summer. However, as Sui's Emperor Wen had died there , Emperor Gaozu did not want to visit Jiucheng Palace. Rather, in 634, Emperor Taizong began to construct another summer palace, Daming Palace , to serve as Emperor Gaozu's summer palace, but Emperor Gaozu fell ill before it was completed, and he never visited Daming Palace. He died in spring 635.

Era name

* ''Wude'' 618-626

Chancellors during reign

* Pei Ji
* Liu Wenjing
* Xiao Yu
* Dou Kang
* Chen Shuda
* Yang Gongren
* Feng Deyi
* Pei Ju
* Yuwen Shiji
* Gao Shilian
* Fang Xuanling

Personal information

* Father
** Li Bing , Duke Ren of Tang during Sui Dynasty, posthumously honored as Emperor Yuan
* Mother
** Duchess Dugu, daughter of Dugu Xin and sister of of Northern Zhou and Empress Dugu Qieluo of Sui Dynasty, posthumously honored as Empress Dowager Yuanzhen
* Wife
** Duchess Dou, daughter of Dou Yi the Duke of Shenwu during Northern Zhou and Sui Dynasty and the Princess Xiangyang, daughter of Yuwen Tai, posthumously honored as Empress Taimushunsheng, mother of Crown Princes Jiancheng and Shimin, Li Xuanba, Prince Yuanji and Princess Pingyang
* Major Concubines
** Consort Wan, mother of Li Zhiyun
** Consort Yin, mother of Prince Yuanheng
** Consort Mo, mother of Prince Yuanjing
** Consort Sun, mother of Prince Yuanchang
** Consort Yuwen, mother of Princes Yuanjia and Lingkui, daughter of Yuwen Shu
** Consort Cui, mother of Prince Yuanyu
** Consort Yang, mother of Prince Yuanxiang
** Consort Yang, mother of Prince Yuanming
** Consort Guo, mother of Prince Yuanli
** Consort Liu, mother of Prince Yuanqing
** Consort Yang, mother of Prince Feng
** Consort Zhang, mother of Prince Yuangui
** Consort Zhang, mother of Prince Yuanyi
** Consort Liu, mother of Prince Yuanying
** Consort Wang, mother of Prince Yuanze
** Consort Lu, mother of Prince Yuanxiao
** Consort Zhang, mother of Prince Yuanfang
* Children
** Li Jiancheng , initially the Duke of Longxi , later the Heir Apparent of Tang , later the Crown Prince
** Li Shimin , initially the Duke of Dunhuang , later the Duke of Zhao , later the Prince of Qin , later the Crown Prince , later Emperor Taizong of Tang
** Li Xuanba , died early without issue, posthumously honored 618 as Prince Huai of Wei
** Li Yuanji , initially the Duke of Guzang , later the Duke of Qi , later the Prince of Qi
** Li Zhiyun , executed by Sui Dynasty official Yin Shishi , posthumously created the Duke of Chu 617, posthumously created Prince Ai of Chu 618
** Li Yuanjing , initially the Prince of Zhao , later the Prince of Jing , later posthumously created the Prince of Shenli
** Li Yuanchang , initially the Prince of Lu , later the Prince of Han
** Li Yuanheng , the Prince of Feng
** Li Yuanfang , the Prince of Zhou
** Li Yuanli , initially the Prince of Zheng , later the Prince of Xu
** Li Yuanjia , initially the Prince of Song , later the Prince of Xu , later the Prince of Han
** Li Yuanze , initially the Prince of Jing , later Prince Si of Peng
** Li Yuanyi , initially the Prince of Teng , later Prince Hui of Zheng
** Li Yuangui , initially the Prince of Shu , later the Prince of Wu , later the Prince of Huo
** Li Feng , initially the Prince of Bin , later Prince Zhuang of Guo
** Li Yuanqing , initially the Prince of Han , later the Prince of Chen , later Prince Xiao of Dao
** Li Yuanyu , initially the Prince of Gui , later Prince Kang of Deng
** Li Yuanming , initially the Prince of Qiao , later the Prince of Shu
** Li Lingkui , initially the Prince of Wei , later the Prince of Yan , later the Prince of Lu
** Li Yuanxiang , initially the Prince of Xu , later Prince An of Jiang
** Li Yuanxiao , Prince Zhen of Mi
** Li Yuanying , the Prince of Teng
** Princess Changsha
** Princess Xiangyang
** Princess Gaomi
** Princess Guiyang, later Princess Changguang
** Princess Wanchun, later Princess Changsha
** Princess Yongjia, later Princess Fangling
** Princess Jiujiang
** Princess Lujiang
** Princess Nanchang
** Princess Anping
** Princess Huainan
** Princess Zhending
** Princess Hengyang
** Princess Danyang
** Princess Linhai
** Princess Guantao
** Princess Qianjin, later Princess Anding
** Princess Changle

Emperor Taizong of Tang

Emperor Taizong of Tang , personal name Lǐ Shìmín , was the second emperor of the Tang Dynasty of China, ruling from 626 to 649. As he encouraged his father, to rise against Sui Dynasty rule at Taiyuan in 617 and subsequently defeated several of his most important rivals, he was ceremonially regarded as a cofounder of the dynasty along with Emperor Gaozu.

He is typically considered one of the greatest, if not the greatest, emperor in all of Chinese history. Throughout the rest of Chinese history, Emperor Taizong's reign was regarded as the exemplary model against which all other emperors were measured, and his "Reign of Zhen'guan" was considered a golden age of Chinese history and required study for future crown princes. During his reign, Tang China flourished economically and militarily. For more than a century after his death, Tang China enjoyed peace and prosperity.

In 630, Emperor Taizong sent his general Li Jing against Eastern Tujue -- to which Tang had once submitted -- defeating and capturing its Jiali Khan Ashina Duobi and destroying Eastern Tujue power. This made Tang the dominant power in East and Central Asia, and Emperor Taizong subsequently took the title of ''Tian Kehan'' .

Emperor Taizong was, in opposition to nobility of the time, a frank rationalist, openly laughing of superstitions and heaven's claimed signs, and modifying important rites in order to ease agricultural labour. The modern Chinese historian Bo Yang opined that Emperor Taizong achieved greatness by accepting criticism that others would find difficult to accept and trying hard not to abuse his absolute power , as well as employing capable Fang Xuanling, Du Ruhui, and Wei Zheng. Emperor Taizong's wife Empress Zhangsun served as a capable assistant to him as well.


Li Shimin was born in 599 at . His father the Duke of Tang was a general of the Sui Dynasty and a nephew, by marriage, to Sui's founding emperor , as Li Shimin's grandmother Duchess Dugu was a sister of Empress Dugu Qieluo -- both were daughters of Dugu Xin , a major general during Sui's predecessor dynasty Northern Zhou. Li Shimin's mother was Li Yuan's wife Duchess Dou, who was a daughter of Dou Yi the Duke of Shenwu and Dou Yi's wife, Northern Zhou's Princess Xiangyang. Duchess Dou bore Li Yuan four sons -- an older brother to Li Shimin, Li Jiancheng, and two younger brothers, Li Xuanba and Li Yuanji -- and at least one daughter . Li Yuan named Li Shimin "Shimin" as a shortened form of the phrase "save the earth and pacify the people" . Li Shimin apparently showed talent early in his life, and in 613, the official Gao Shilian, impressed with him, gave him a niece in marriage as his wife; he was 14 and she was 12. In 615, when Emperor Wen's son and successor was ambushed by Eastern Tujue forces at Yanmen , a general call was made for men to join the army to help rescue the emperor. Li Shimin answered that call and served under the general Yun Dingxing , apparently doing so with distinction. In 616, when Li Yuan was put in charge of the important city of Taiyuan, Li Shimin followed his father to Taiyuan, while leaving at least three other sons -- Li Jiancheng, Li Yuanji, and Li Zhiyun -- at the ancestral home Hedong .

Participation in the rebellion against Sui rule

Emperor Yang was soon dissatisfied with Li Yuan and Wang Rengong , the governor of Mayi Commandery , over their inability to stop Eastern Tujue incursions and the growing strengths of agrarian rebels, particularly the Eastern Tujue-support Liu Wuzhou the Dingyang Khan, who soon rose against Wang and killed him and soon captured Emperor Yang's secondary palace near Taiyuan. Li Yuan also became fearful that there had been prophecies throughout the empire that the next emperor would be named Li -- and that Emperor Yang had killed another official, Li Hun and Li Hun's clan over his fears that Li Hun's nephew, Li Min , would seize the throne.

In fear, Li Yuan considered rebellion, and at that point, he did not know that Li Shimin had also been doing so -- secretly discussing such plans with Li Yuan's associates Pei Ji and Liu Wenjing. Once Li Shimin's plans matured, he had Pei inform Li Yuan of them -- and also had Pei warn Li Yuan that if it were revealed that Li Yuan had had sexual relations with some of Emperor Yang's at the secondary Jinyang Palace , all of them would be slaughtered. Li Yuan agreed to rebel, and after secretly summoning Li Jiancheng and Li Yuanji from Hedong and his son-in-law Chai Shao from the capital Chang'an, he declared a rebellion, claiming to want to support Emperor Yang's grandson the Prince of Dai, nominally in charge at Chang'an with Emperor Yang at Jiangdu , as emperor. He made both Li Jiancheng and Li Shimin major generals and advanced southwest, toward Chang'an. He created Li Shimin the Duke of Dunhuang.

However, when Li Yuan arrived near Hedong, his army was bogged down by the weather, and with food running out, there were rumors that Eastern Tujue and Liu Wuzhou would attack Taiyuan. Li Yuan initially ordered retreat, but at the earnest opposition by Li Jiancheng and Li Shimin, continued to advance. After defeating Sui forces at Huoyi , he decided to leave a small contingent to watch over Hedong while advancing across the Yellow River into Guanzhong . Once he did, he headed for Chang'an himself, while sending Li Jiancheng to capture the territory around the Tong Pass region to prevent Sui forces at Luoyang from reinforcing Chang'an and Li Shimin north of the Wei River to capture territory there. Meanwhile, Li Shimin's sister had also risen in rebellion in support of him, and she was able to gather a sizable army and capture some cities. She joined forces with Li Shimin and her husband Chai Shao. Soon, Li Yuan reconsolidated his forces and put Chang'an under siege. In winter 617, he captured Chang'an and declared Yang You emperor . He had himself made regent and created the Prince of Tang. He created Li Shimin the Duke of Qin.

Li Yuan's control of the Chang'an region became almost immediately contested by the rebel ruler Xue Ju the Emperor of Qin, who sent his son Xue Rengao toward Chang'an. Li Yuan sent Li Shimin to resist Xue Rengao, and Li Shimin defeated Xue Rengao at Fufeng , temporarily causing Xue Ju to toy with the idea of surrendering to Li Yuan, although Xue was subsequently dissuaded by his strategist Hao Yuan from doing so.

In spring 618, with Sui's eastern capital Luoyang under attack by the rebel ruler Li Mi the Duke of Wei, Li Yuan sent Li Jiancheng and Li Shimin to Luoyang, ostensibly to aid the Sui forces at Luoyang but instead intending to test whether Luoyang might submit to him. The officials at Luoyang rebuffed his attempt at rapprochement, and Li Jiancheng and Li Shimin, not wanting to fight either them or Li Mi for control of Luoyang at this stage, withdrew. Li Yuan subsequently changed Li Shimin's title to Duke of Zhao.

In summer 618, when news arrived at Chang'an that Emperor Yang had been killed at Jiangdu in a coup led by the general Yuwen Huaji, Li Yuan had Emperor Gong yield the throne to him, establishing Tang Dynasty as its Emperor Gaozu. He created Li Jiancheng crown prince but created Li Shimin the Prince of Qin, also making him ''Shangshu Ling'' , the head of the executive bureau of the government and a post considered one for a , while continuing to have Li Shimin serve as a major general as well.

During Emperor Gaozu's reign

The campaign to reunify the empire

The first thing that Li Shimin had to deal with was another incursion by Xue Ju, as Xue attacked Jing Prefecture and Emperor Gaozu sent Li Shimin to resist Xue. Li Shimin established his defenses and refused to engage Xue to try to wear Xue Ju out, but at that time, he was afflicted with malaria, and he let his assistants Liu Wenjing and Yin Kaishan take command, ordering them not to engage Xue Ju. Liu and Yin, however, did not take Xue Ju seriously, and Xue Ju ambushed them at Qianshui Plain , crushing Tang forces and inflicting 50%-60% casualties. Li Shimin was forced to withdraw back to Chang'an, and Liu and Yin were removed from their posts. Xue Ju, in light of his victory, was ready to launch an assault on Chang'an itself, under Hao Yuan's advice, but suddenly died of an illness in fall 618 and was succeeded by Xue Rengao. Emperor Gaozu then sent Li Shimin against Xue Rengao. Three months after Xue Rengao took the throne, Li Shimin engaged him, and after a fierce battle between Li Shimin and Xue Rengao's major general Zong Luohou , Li Shimin crushed Zong's forces, and then attacked Xue Rengao. Xue Rengao was forced to withdraw into the city of Gaozhi , and once he did, his soldiers began surrendering to Li Shimin in mass. Xue Rengao was himself forced to surrender. Li Shimin had him delivered to Chang'an, where he was executed. Around new year 619, Emperor Gaozu made Li Shimin ''Taiwei'' and made him in charge of Tang operations east of the Tong Pass.

In spring 619, Liu Wuzhou launched a major offensive against Tang. He captured Taiyuan in summer 619, forcing Li Yuanji, who had been in charge there, to flee, and then continued his offensive south. Emperor Gaozu sent Pei Ji against him, but by winter 619, Liu had crushed Pei's forces and taken over nearly all of modern Shanxi. Emperor Gaozu, shocked at the development, considered abandoning the region altogether. Li Shimin opposed doing so and offered to lead the army against Liu. Emperor Gaozu agreed and commissioned him with an army. He crossed the Yellow River and approached LIu's major general Song Jin'gang but did not engage him, choosing to try to wear Song out, only having his subordinates Yin Kaishan and Qin Shubao engage the other Dingyang generals Yuchi Jingde and Xun Xiang in relatively low-level engagements. Eventually, in spring 620, when Liu and Song ran out of food supplies, they retreated, and Li Shimin gave chase, dealing Song a major defeat. Yuchi and Xun surrendered, and after Li Shimin chased further, both Liu and Song fled to Eastern Tujue. All of Dingyang territory fell into Tang hands.

In summer 620, Emperor Gaozu again commissioned Li Shimin against a major enemy -- the former Sui general Wang Shichong, who had Sui's last emperor, Emperor Yang's grandson Yang Tong, yield the throne to him in 619, establishing a new state of Zheng as its emperor. When Li Shimin arrived at the Zheng capital Luoyang, Wang offered peace, but Li Shimin rebuffed him and put Luoyang under siege. Meanwhile, his subordinates took Zheng cities one by one. By winter 620, most of Zheng territory, other than Luoyang and Xiangyang, defended by Wang Shichong's nephew Wang Honglie , had submitted to Tang. Wang sought aid Dou Jiande the Prince of Xia, who controlled most of modern Hebei. Dou, reasoning that if Tang were able to destroy Zheng, his own Xia state would be corner, agreed. He sent his official Li Dashi to try to persuade Li Shimin to withdraw, but Li Shimin detained Li Dashi and gave no response. Meanwhile, during the campaign, Li Shimin chose some 1,000 elite soldiers, clad in black uniform and black armor, commanded by himself, to serve as advance forward troops, with Qin, Cheng Zhijie , Yuchi, and Zhai Zhangsun as his assistants.

By spring 621, Luoyang was in desperate situation, and Xia forces had not yet arrived, but Tang troops had also suffered serious casualties, as Luoyang's defenses, aided by powerful bows and catapults, were holding. Emperor Gaozu, hearing that Dou had decided to come to Wang's aid, ordered Li Shimin to withdraw, but Li Shimin sent his secretary Feng Deyi to Chang'an to explain to Emperor Gaozu that if he did withdraw, Wang would recover and again be a major threat in the future. Emperor Gaozu agreed and allowed Li Shimin to continue to siege Luoyang. When Xia forward troops arrived first, Li Shimin surprised and defeated them, and then sent Dou a letter suggesting that he withdraw. Dou would not do so, and, against the advice of his wife and secretary general Ling Jing that he should instead attack Tang's prefectures in modern southern Shanxi, he marched toward Luoyang. Anticipating Dou's maneuver, Li Shimin left a small detachment, commanded by Li Yuanji, at Luoyang, while marching east himself, taking up position at the strategic Hulao Pass. When the armies engaged at Hulao, Li Shimin defeated Dou and captured him. He took Dou back to Luoyang and displayed him to Wang Shichong. Wang, in fear, considered abandoning Luoyang and fleeing south to Xiangyang, but as his generals pointed out that his only hope was Dou, he surrendered. Xia forces, after initially fleeing back to the Xia capital Ming Prefecture , also surrendered. Zheng and Xia territory were Tang's. Li Shimin returned to Chang'an in a grand victory procession, and, to reward Li Shimin, Emperor Gaozu awarded both him and Li Yuanji three mints so that they could mint money of their own. He also bestowed on Li Shimin the special title of "Grand General of Heavenly Strategies" . Meanwhile, Li Shimin's staff, already full of generals and strategists, were now being supplemented with a number of literary men.

The former Xia territory did not remain in Tang hands for long, as in winter 621, the Xia general Liu Heita rose against Tang rule, claiming to be avenging Dou, whom Emperor Gaozu had executed after Li Shimin took him back to Chang'an . He was allied with Xu Yuanlang, a former agrarian rebel general who was nominally under Wang Shichong and who had submitted to Tang after Wang's defeat. Liu dealt successive defeats to Emperor Gaozu's cousin Li Shentong the Prince of Huai'an, Li Xiaochang the Prince of Yi'an, and Li Shiji. Emperor Gaozu sent Li Shimin and Li Yuanji against Liu. In 622, after some indecisive battles with Liu, who had by that point taken over almost all of former Xia territory and claimed the title of Prince of Handong, Li Shimin defeated Liu by flooding his army with water from the Ming River , and Liu fled to Eastern Tujue. Li Shimin then headed east and attacked Xu, defeating him. After leaving Li Shiji, Li Shentong, and Ren Gui to continue to attack Xu, Li Shimin returned to Chang'an.

The struggle against Li Jiancheng and Li Yuanji

By this point, Li Shimin and his older brother Li Jiancheng, who was created crown prince in 618, reportedly after Emperor Gaozu first offered the position to Li Shimin due to his contributions, were locked in an intense rivalry, as Li Shimin's accomplishments caused people to speculate that he would displace Li Jiancheng as crown prince, and Li Jiancheng, while an accomplished general himself, was overshadowed by his younger brother. The court became divided into a faction favoring the Crown Prince and a faction favoring the Prince of Qin. The rivalry was particularly causing problems within capital, as the commands of the Crown Prince, the Prince of Qin, and the Prince of Qi were said to have the same force as the emperor's edicts, and the officials had to carry conflicting orders out by acting on the ones that arrived first. Li Shimin's staff was full of talented men, but Li Jiancheng was supported by Li Yuanji, as well as Emperor Gaozu's concubines, who had better relationships with Li Jiancheng and Li Yuanji than they did with Li Shimin.

Late in 622, when Liu Heita returned to former Xia domain after receiving aid from Eastern Tujue, defeating and killing Li Shimin's cousin Li Daoxuan the Prince of Huaiyang, he again regained most of former Xia territory. Li Jianheng's staff members Wang Gui and Wei Zheng suggested that Li Jiancheng needed to enhance his own reputation in battle, and so Li Jiancheng volunteered for the mission. Emperor Gaozu thus sent Li Jiancheng, assisted by Li Yuanji, to attack Liu. Li Jiancheng defeated Liu around the new year 623, and Liu was subsequently betrayed by his own official Zhuge Dewei and delivered to Li Jiancheng. Li Jiancheng killed Liu and returned to Chang'an in triumph. China was, by this point, roughly united under Tang rule.

For the next few years, the rivalry intensified, although during the meantime both Li Jiancheng and Li Shimin served as generals when Eastern Tujue made incursions. In 623, when the general Fu Gongshi rebelled at Danyang , Emperor Gaozu briefly commissioned Li Shimin to attack Fu, but soon cancelled the order and sent Li Shimin's cousin Li Xiaogong the Prince of Zhao Commandery instead.

In 624, when Li Jiancheng was found to have, against regulations, tried to add soldiers to his guard corps, Emperor Gaozu was so angry that he put Li Jiancheng under arrest. In fear, Li Jiancheng's guard commander Yang Wen'gan rebelled. Emperor Gaozu sent Li Shimin against Yang, offering to make him crown prince after he returned. After Li Shimin left, however, Feng Deyi , Li Yuanji, and the concubines all spoke on Li Jiancheng's behalf, and after Li Shimin returned, Emperor Gaozu did not depose Li Jiancheng, but instead blamed the discord between him and Li Shimin on Li Jiancheng's staff members Wang Gui and Wei Ting and Li Shimin's staff member Du Yan, exiling them to Xi Prefecture .

Later that year, Emperor Gaozu, troubled by repeated Eastern Tujue incursions, seriously considered burning Chang'an to the ground and moving the capital to Fancheng, a suggestion that Li Jiancheng, Li Yuanji, and Pei Ji agreed with. Li Shimin opposed, however, and the plan was not carried out. Meanwhile, Li Shimin himself was sending his confidants to Luoyang to build up personal control of the army there. After an incident in which Li Shimin suffered a severe case of food poisoning after feasting at Li Jiancheng's palace -- an event that both Emperor Gaozu and Li Shimin apparently interpreted as an assassination attempt -- Emperor Gaozu considered sending Li Shimin to guard Luoyang to prevent further conflict, but Li Jiancheng and Li Yuanji, after consulting each other, believed that this would only give Li Shimin an opportunity to build up his personal power there, and therefore opposed it. Emperor Gaozu therefore did not carry out the plan. Meanwhile, the rivalry continued. Traditional historical accounts also indicated that at one point, when Li Shimin visited Li Yuanji's mansion, Li Yuanji wanted to assassinate Li Shimin, but Li Jiancheng, who could not resolve to kill a brother, stopped the plot. There was yet another incident in which Li Jiancheng, knowing that a horse threw its rider easily, had Li Shimin ride it, causing Li Shimin to fall off from it several times.

By 626, Li Shimin was fearful that he would be killed by Li Jiancheng, and his staff members Fang Xuanling, Du Ruhui, and Zhangsun Wuji were repeatedly encouraging Li Shimin to attack Li Jiancheng and Li Yuanji first -- while Wei Zheng was encouraging Li Jiancheng to attack Li Shimin first. Li Jiancheng persuaded Emperor Gaozu to remove Fang and Du, as well as Li Shimin's trusted guard officers Yuchi Jingde and Cheng Zhijie, from Li Shimin's staff. Zhangsun, who remained on Li Shimin's staff, continued to try to persuade Li Shimin to attack first.

In summer 626, Eastern Tujue was making another attack, and under Li Jiancheng's suggestion, Emperor Gaozu, instead of sending Li Shimin to resist Eastern Tujue as he first was inclined, decided to send Li Yuanji instead. Li Yuanji was given command of much of the army previously under Li Shimin's control, further troubling Li Shimin, who believed that with the army in Li Yuanji's hands, he would be unable to resist an attack. Li Shimin had Yuchi summon Fang and Du back to his mansion secretly, and then on one night submitted an accusation to Emperor Gaozu that Li Jiancheng and Li Yuanji were committing adultery with Emperor Gaozu's concubines. Emperor Gaozu, in response, issued summonses to Li Jiancheng and Li Yuanji for the next morning, convening the senior officials Pei Ji, Xiao Yu, and Chen Shuda to examine Li Shimin's accusations. As Li Jiancheng and Li Yuanji approached the central gate leading to Emperor Gaozu's palace, Xuanwu Gate , Li Shimin carried out the ambush he had set. He personally fired an arrow that killed Li Jiancheng. Subsequently, Yuchi killed Li Yuanji. Li Shimin's forces entered the palace and, under the intimidation of Li Shimin's forces, Emperor Gaozu agreed to create Li Shimin crown prince. Li Jiancheng's and Li Yuanji's sons were killed, and Li Shimin took Li Yuanji's wife Princess Yang as a concubine. Two months later, with Li Shimin firmly in control of power, Emperor Gaozu yielded the throne to him .

Early reign

One of the first actions that Emperor Taizong carried out as emperor was releasing a number of from the palace and returning them to their homes, so that they could be married. He created his wife Princess Zhangsun as empress, and their oldest son Li Chengqian as crown prince.

Emperor Taizong also immediately faced a crisis, as Eastern Tujue's Jiali Khan Ashina Duobi, along with his nephew the subordinate Tuli Khan Ashina Shibobi , launched a major incursion toward Chang'an, and just 19 days after Emperor Taizong took the throne, the two khans were just across the Wei River from Chang'an. Emperor Taizong, accompanied by Gao Shilian and Fang Xuanling, was forced to meet Ashina Duobi across the river and personally negotiate peace terms, including tributes to Eastern Tujue, before Ashina Duobi withdrew.

Late in 626, Emperor Taizong ranked the contributors to Tang rule and granted them titles and fiefs, naming among the first rank of contributors Zhangsun Wuji, Fang, Du Ruhui, Yuchi Jingde, and Hou Junji. When Li Shentong, as his distant uncle, objected to being ranked under Fang and Du, Emperor Taizong personally explained how Fang and Du's strategies allowed him to be successful, and this managed to get the other objectors to quiet down, as Emperor Taizong was even willing to rank low such an honored individual as Li Shentong. Emperor Taizong also buried Li Jiancheng and Li Yuanji with honors due imperial princes and had their staff members attend the funeral processions. Meanwhile, he appeared to began to reshuffle government further -- which he had already begun after being created crown prince -- by dismissing his father's trusted advisors Xiao Yu and Chen Shuda, making his own trusted advisors chancellors. However, he also began to greatly pay attention to the officials' submissions and their criticism of imperial governance, making changes where he saw needed. He also particularly began to trust Wei Zheng, accepting much advice from Wei as far as his personal conduct was concerned. He was also willing to demote his own trusted advisors, as he demoted Gao after finding that Gao had held back submissions from his deputy Wang Gui. Viewing Sui's Emperor Yang as a negative example, he frequently solicited criticism, rewarding those officials willing to offer them, particularly Wei and Wang Gui.

Also in 627, the general the Prince of Yan -- a late-Sui warlord who later submitted to Tang, who associated with Li Jiancheng -- fearing that Emperor Taizong would eventually take action against him, rebelled at Bin Prefecture , but was quickly crushed by the official Yang Ji and killed in flight. Later that year, when Emperor Gaozu's cousin Li Youliang the Prince of Changle, the commandant at Liang Prefecture , was accused of allowing his staff to oppress the people and to trade with Qiang and Xiongnu tribesmen, Emperor Taizong sent the chancellor Yuwen Shiji to investigate, and in fear, Li Youliang's staff members plotted to hold him hostage and rebel. When this was discovered, Emperor Taizong forced Li Youliang to commit suicide. Late in the year, Wang Junkuo , the commandant at You Prefecture , also rebelled, but was defeated quickly and killed in flight. However, although there were also reports that Feng Ang , a warlord in the modern Guangdong region, was rebelling, Emperor Taizong, at Wei's suggestion, sent messengers to comfort Feng, and Feng submitted.

Also in 627, Emperor Taizong, seeing that there were too many prefectures and counties, consolidated and merged many of them, and further created another level of local political organization above prefectures -- the circuit -- dividing his state into 10 circuits.

In 628, with Ashina Duobi and Ashina Shibobi having a fallout, Ashina Shibobi submitted to Emperor Taizong, as did the chieftains of Khitan tribes, who had previously submitted to Eastern Tujue. With Eastern Tujue in turmoil, Ashina Duobi was no longer able to protect the last late-Sui rebel ruler who along remained standing against Tang pressure -- Liang Shidu the Emperor of Liang, and in summer 628, with the Tang generals Chai Shao and Xue Wanjun sieging the Liang capital Shuofang , Liang Shidu's cousin Liang Luoren killed Liang Shidu and surrendered, finally uniting China. With Eastern Tujue weakened, Eastern Tujue's vassal Xueyantuo also broke away and formed its own khanate, and Emperor Taizong entered into an alliance with Xueyantuo's leader Yi'nan, creating Yi'nan the Zhenzhupiqie Khan .

In late 629, believing the time ripe for a major attack on Eastern Tujue, Emperor Taizong commissioned the general Li Jing with overall command of a multi-pronged army, assisted by the generals Li Shiji, Chai, and Xue Wanche , attacking Eastern Tujue at multiple points. The army was successful in its attacks, forcing Ashina Duobi to flee, and by late spring 630, Ashina Duobi had been captured, and Eastern Tujue chieftains all submitted to Tang. Emperor Taizong spared Ashina Duobi but detained him at Chang'an, and he considered what to do with the Eastern Tujue people. The main opposing views were from the chancellors Wen Yanbo and Wei . Emperor Taizong accepted Wen's suggestion and established a number of prefectures to accommodate the Eastern Tujue people, still leaving them governed by their chieftains, without creating a new khan to govern them.

In 631, Emperor Taizong established a scheme, where the contributors to his reign were given, in addition to their current posts, additional posts as prefectural governors, to be passed on to their descendants. Soon, however, receiving much opposition to the plan, the strongest of which came from Zhangsun Wuji, Emperor Taizong cancelled the scheme.

After the conquest of Eastern Tujue, Emperor Taizong's officials repeatedly requested that he carry out sacrifices to heaven and earth at Mount Tai, and Emperor Taizong, while at times tempted by the proposal, was repeatedly dissuaded from doing so by Wei, who pointed out the expenses and the labors that would be imposed on the people as a result, and also that this would open China's borders to attack.

Middle reign

In 634, Emperor Taizong sent 13 high level officials, including Li Jing and Xiao Yu, to examine the circuits to see whether the local officials were capable, to find out whether the people were suffering, to comfort the poor, and to select capable people to serve in civil service.

Around this time, Tang was having increasing conflicts with Tuyuhun, whose Busabo Khan Murong Fuyun, under instigation by his strategist the Prince of Tianzhu, had been repeatedly attacking Tang prefectures on the borders. At one point, Murong Fuyun sought to have a Tang princess marry his son the Prince of Zun, but the marriage negotiations broke down over Emperor Taizong's insistence that the Prince of Zun come to Chang'an for the wedding. In summer 634, Emperor Taizong had the generals Duan Zhixuan and Fan Xing lead forces against Tuyuhun, but with Tuyuhun's forces highly mobile and avoiding direct confrontation, Duan, while not defeated, could not make major gains. Once Duan withdrew, Tuyuhun resumed hostilities. In winter 634, with the Tufan king Songts& making overtures to marry a Tang princess as well, Emperor Taizong sent the emissary Feng Dexia to Tufan with an eye toward an alliance against Tuyuhun. In winter 634, he commissioned Li Jing, assisted by the other generals Hou Junji, Li Daozong, Li Daliang , Li Daoyan , and Gao Zengsheng , to attack Tuyuhun. In 635, Li Jing's forces crushed Tuyuhun forces. Murong Fuyun was killed by his own subordinates, and his son Murong Shun killed the Prince of Tianzhu and surrendered. Emperor Taizong created Murong Shun the new khan, although Murong Shun was soon assassinated. Emperor Taizong then created Murong Shun's son Murong Nuohebo as the new khan.

Also in 635, Emperor Gaozu died, and Emperor Taizong, observing a mourning period, briefly had Li Chengqian serve as regent, and after he resumed his authorities less than two months later, he still authorized Li Chengqian to thereafter rule on minor matters.

In spring 636, Emperor Taizong commissioned his brothers and sons as commandants and changed their titles in accordance with the commands that they received, sending them to their posts -- with the exception of his son Li Tai the Prince of Wei, who by this point was beginning to be highly favored by him. He further allowed Li Tai to engage literary men to serve as his assistants, as Li Tai favored literature. From this point on, Li Tai would be so favored that there began to be talks that Emperor Taizong might let him displace Li Chengqian, whose favors began to wane.

In fall 636, Empress Zhangsun died. Emperor Taizong mourned her bitterly and personally wrote the text of her monument.

In summer 637, Emperor Taizong recreated the feudal scheme that he had considered and abandoned in 631, creating 35 hereditary prefect posts.

Sometime before 638, Emperor Taizong, disgusted with the traditional noble clans of Cui, Lu, Li, and Zheng and believing that they were abusing their highly honored names, commissioned Gao Shilian, Wei Ting, Linghu Defen, and Cen Wenben to compile a work later to be known as the ''Records of Clans'' , with the intent of dividing the clans into nine classes based on their past contributions, good deeds, and ill deeds. In an initial draft that Gao submitted, he nevertheless ranked the branch of the Cui clan that the official Cui Min'gan belonged to as the highest, a decision that Emperor Taizong rebuked, as he pointed out that Gao was merely again looking at tradition and not the recent contributions. He therefore personally intervened in revising the work, reducing Cui's clan to the third class.

In fall 638, Tufan's Songtsän Gampo, displeased that Emperor Taizong had declined to give him a Tang princess in marriage and believing that Murong Nuohebo had persuaded Emperor Taizong to decline the marriage proposal, launched a major attack with forces of 200,000 on Tuyuhun and then on several Tang prefectures, putting Song Prefecture under siege. Emperor Taizong commissioned Hou, assisted by Zhishi Sili , Niu Jinda , and Liu Jian , of a total of force of 50,000 to counterattack, and Niu, who commanded the forward forces, defeated Tufan forces at Song Prefecture. Songsän Gampo withdrew and sued for peace, but still sought to marry a Tang princess. Emperor Taizong agreed this time.

Also in 638, believing that Xueyantuo was growing increasingly strong and difficult to control, Emperor Taizong granted Yi'nan's sons and Jialibi both lesser khan titles, to try to create dissensions between them.

In summer 639, Ashian Jiesheshuai , the younger brother of Ashina Shibobi, whom Emperor Taizong did not favor and gave little recognition to, formed a conspiracy with Ashina Shibobi's son Ashina Hexiangu to assassinate Emperor Taizong. They had planned to wait for the Prince of Jin to depart from the palace in the morning and use that opportunity to attack the palace. On the day they planned, however, Li Zhi did not leave the palace, and Ashina Jiesheshuai attacked anyway but was quickly defeated, captured, and executed. After this incident, however, the officials began advocating sending the Tujue people away from the heart of the state. In fall 639, Emperor Taizong created a Tujue prince who had served him faithfully, Li Simo as the khan of a newly recreated Eastern Tujue state , giving him all of the Tujue and Xiongnu who had surrendered as his subordinates, to be settled north of the Great Wall and the Yellow River. However, the Tujue people were fearful of Xueyantuo and initially refused to head to their new location. Emperor Taizong issued an edict to Yi'nan that he and Li Simo keep their peace and not attack each other, and after receiving from Yi'nan the assurance that he would not attack, the Tujue people advanced to the new location.

Meanwhile, Qu Wentai , the king of Gaochang, who had previously been submissive to Tang, had become increasingly hostile to Tang, allying with Western Tujue. In 640, Emperor Taizong commissioned Hou, assisted by Xue Wanjun, to launch a major attack on Gaochang. As they approached Gaochang, Qu Wentai died in fear and was succeeded by his son Qu Zhisheng . Qu Zhisheng offered to submit, but Hou demanded a surrender, which Qu Zhisheng refused. However, Hou put Gaochang under siege, and with aid from Western Tujue not arriving, Qu Zhisheng surrendered. Wei suggested that Emperor Taizong allow Qu Zhisheng to remain king, pointing out that the monetary and human costs would be high to keep a permanent garrison at Gaochang, but Emperor Taizong disagreed, and he converted Gaochang into two prefectures and annexed it into his state.

In winter 640, Songsän Gampo sent his prime minister Ludongzan as an emissary to Tang, offering tributes and again requesting marriage. Emperor Taizong created a daughter of a clansman as the Princess Wencheng, and in 641 sent Li Daozong to accompany Princess Wencheng to Tufan to preside over the wedding.

In winter 641, believing that Emperor Taizong was about to carry out sacrifices to heaven and earth at Mount Tai and would be unable to aid Eastern Tujue, Yi'nan launched a major attack on Eastern Tujue, commanded by his son Dadu . Li Simo was forced to retreat inside the Great Wall. Emperor Taizong commissioned Li Shiji, assisted by Zhang Jian , Li Daliang, Zhang Shigui , and Li Xiyu , to attack Xueyantuo. Li Shiji soon defeated Dadu at Nuozhen River , and Dadu fled.

Late reign

By 642, it was clear that Li Tai had ambitions on replacing his brother Li Chengqian, and the governmental officials began to be divided into pro-Li Chengqian and pro-Li Tai factions. After urging by Wei Zheng and Chu Suiliang to take actions that would clarify that Li Chengqian's position was secure, Emperor Taizong attempted to do so by making repeated statements to that effect, but his continued favoring of Li Tai led to continued speculation among officials.

Also by 642, Xueyantuo had posed a sufficiently serious threat that Emperor Taizong saw two alternatives -- destroying it by force or forming into a ''heqin'' relationship by marrying one of his daughters to Yi'nan. This particularly became an issue after the Tang general Qibi Heli , the chieftain of the Qibi Tribe, was kidnapped by his own subordinates and taken to Xueyantuo. In order to ransom Qibi, Emperor Taizong made a promise to eventually give his daughter Princess Xinxing to Yi'nan in marriage, and Yi'nan released Qibi.

In the winter 642, an event took place in Goguryeo that would eventually precipitate wars between Tang and Goguryeo. According to Chinese accounts Go Geonmu , the king of Goguryeo, was apprehensive about his general Yeon Gaesomun and was plotting with his other officials to kill Yeon. When Yeon received the news, he started a coup and killed the king and the high level officials. He declared King Yeongnyu's nephew Go Jang king, while taking power himself with the title of ''Mangniji'' . When Emperor Taizong received the news, there were suggestions that an attack be launched against Goguryeo, suggestions that Emperor Taizong initially declined.

In spring 643, Wei died, and Emperor Taizong mourned him bitterly, authoring Wei's monument himself and, prior to Wei's death, promising to give his daughter Princess Hengshan in marriage to Wei's son Wei Shuyu . Later in spring, Emperor Taizong commissioned 24 portraits at Lingyan Pavilion to commemorate the 24 great contributors to his reign.

Also in 643, Emperor Taizong would see major turmoil among his own closest family. In spring 643, his son Li You the Prince of Qi, angry over restrictions that his secretary general Quan Wanji had often placed on him, killed Quan and declared a rebellion. Emperor Taizong sent Li Shiji against Li You, but before Li Shiji could engage Li You, Li You was captured by his own subordinate Du Xingmin and delivered to Chang'an, where Emperor Taizong ordered him to commit suicide and executed 44 of his associates.

The death of Li You drew out news of another plot. Li Chengqian, who had been fearful that Emperor Taizong would eventually remove him and replace him with Li Tai, had begun to conspire with Hou Junji, Li Yuanchang the Prince of Han , the general Li Anyan , and his brothers-in-law Zhao Jie and Du He to overthrow Emperor Taizong. During the investigations in the aftermaths of Li You's rebellion, one of the co-conspirators, Li Chengqian's guard Gegan Chengji , was implicated by association, and in order to save himself, he revealed Li Chengqian's plot. Emperor Taizong was shocked by the news, and he appointed Zhangsun Wuji, Fang Xuanling, Xiao Yu, and Li Shiji, along with the officials in charge of the supreme court and the legislative and examination bureaus of the government to carry out a joint investigation. At the suggestion of the mid-level official Lai Ji, Emperor Taizong deposed, but did not kill, Li Chengqian, while ordering Li Yuanchang to commit suicide and executing Hou, Li Anyan, Zhao, and Du.

After Li Chenqian was deposed, Emperor Taizong briefly promised Li Tai that he would be made crown prince. However, as the investigations continued, Emperor Taizong came to the belief that Li Chengqian's downfall was driven by Li Tai's machinations, and therefore resolved to depose Li Tai as well. At Zhangsun's suggestion, Emperor Taizong created a younger son, the Prince of Jin , crown prince, who was considered kinder and gentler, while exiling Li Chengqian and Li Tai.

Meanwhile, coming to the belief that he made an ill-advised promise to Yi'nan to give him Princess Xinxing in marriage, Emperor Taizong demanded a large amount of bride price -- 50,000 horses, 10,000 cows and camels, and 100,000 sheep -- a price that Yi'nan agreed to, but could not immediately collect and deliver. Emperor Taizong used it as an excuse to cancel the marriage agreement. Meanwhile, as Wei Zheng had, prior to his death, recommended Hou and Li Chengqian's staff member Du Zhenglun as chancellors, Emperor Taizong came to suspect that Wei was part of the plot as well. He destroyed the monument he had authored for Wei and cancelled the betrothal between Wei Shuyu and Princess Hengshan.

In 644, with Yanqi's king Long Tuqizhi , who had assisted the Tang campaign to conquer Gaochang, turning against Tang and allying with Western Tujue, Emperor Taizong sent the general Guo Xiaoke , the commandant at Anxi to launch a surprise attack on Yanqi. Guo caught Long Tuqizhi by surprise and captured him, making his brother Long Lipozhun regent.

Also in 644, with Goguryeo attacking Silla and Silla requesting aid, Emperor Taizong decided to prepare for a campaign to conquer Goguryeo. He arrested the emissaries that Yeon sent to the Tang court, accusing them of disloyalty to King Yeongnyu. By winter 644, the mobilization was in full force.

In spring 645, Emperor Taizong departed from Luoyang and led the troops northeast, behind a vanguard of 60,000 commanded by Li Shiji and Li Daozong. At the same time, Zhang Liang led the other 40,000 from sea. By summer 645, Tang forces had captured Liaodong , and headed southeast toward the Goguryeo capital Pyongyang. Emperor Taizong's 20,000 force defeated a large force of 150,000 commanded by two Gogureyo generals and then put Anshi under siege. However, the capable defense put up by Anshi's commanding general stymied Tang forces and, in late fall, with winter fast approaching and his food supplies running out, Emperor Taizong withdrew. He much regretted launching the campaign and made the comment, "If Wei Zheng were still alive, he would never have let me launch this campaign." He reerected the monument he authored for Wei and summoned Wei's wife and children to meet him, treating them well. He also began to suffer from an illness -- an illness that he would never appear to completely recover from.

Meanwhile, in the aftermaths of the Goguryeo campaign, Xueyantuo's Duomi Khan Bazhuo launched attacks against Tang's border prefectures, with largely inconclusive results. In spring 646, the Tang generals Qiao Shiwang and Zhishi Sili counterattacked, defeating Bazhuo's forces, causing him to flee. His vassals Huige, Pugu , and Tongluo tribes took the opportunity to rebel and attack him. Hearing this, Emperor Taizong launched a major attack, commanded by Li Daozong, Ashina She'er , Zhishi, Qibi, Xue Wanche, and Zhang Jian, against Xueyantuo. With Xueyantuo under attack from multiple sides, Bazhuo was killed by Huige forces, and the remaining Xueyantuo people fled and supported Bazhuo's cousin Duomozhi as Yitewushi Khan, but soon offered to submit to Tang. Emperor Taizong sent Li Shiji toward Duomozhi's location, with the direction to either accept his submission or destroy him. Duomozhi surrendered and was taken to Chang'an, ending Xueyantuo's rule over the region. The other tribes formerly submissive to Xueyantuo offered Emperor Taizong the title of "Heavenly Khan" and thereafter largely became submissive to Tang. Tang nominally established seven command posts and six prefectures over the region.

After the victory over Xueyantuo, Emperor Taizong again turned his attention toward to Goguryeo, cutting off relations once more and considering another campaign. Under suggestions by some of his officials, he decided to launch harassment campaigns against Goguryeo's northern region on a yearly basis, to weaken Goguryeo gradually. The first of these campaigns was launched in spring 647, with Niu Jinda and Li Shiji in command, and would reoccur. All this was in preparation of another campaign in 649 with forces totaling 300,000, but Taizong died before this campaign and the campaign was stalled into Gaozong's reign.

In 648, Emperor Taizong launched another campaign, commanded by Ashina She'er, aimed at , but first attacking Yanqi and killing Long Xuepoanazhi and replacing him with his cousin Long Xiannazhun . Ashina She'er advanced on Qiuzi and captured its king Bai Helibushibi , making his brother king instead.

By summer of 649, Emperor Taizong was seriously ill -- with some believing that his illness was caused by his taking pills given him by . Believing Li Shiji to be capable but fearing that he would not be submissive to Li Zhi, he demoted Li Shiji out of the capital to be the commandant at remote Die Prefecture , with instructions to Li Zhi that if Li Shiji hesitated, to execute him immediately, and if he did not, to recall him after Emperor Taizong's death and make him chancellor. Li Shiji, when receiving the order and realizing that his life was at stake, immediately departed for Die Prefecture. Soon thereafter, Emperor Taizong, after entrusting Li Zhi to Zhangsun Wuji and Chu, died at his summer palace Cuiwei Palace . His death was initially kept a secret, and three days later, after his casket had been returned to Chang'an, his death was announced, and Li Zhi took the throne as Emperor Gaozong.

Taizong "reign" 616-649

Colors show the succession of Taizong conquest in Asia :

{鄰) of the . The novel is also known as ''The Biography of the Prince of Qin of the Tang Dynasty'' , ''Romance of Tang'' , and '' Romance of the Prince of Qin'' .
* Hong Kong TVB made a TV drama about Li Shimin's adventure based on the ''The Novel of the Prince of Qin of the Great Tang'' . TVB's 1983 martial arts drama ''The Foundation'' also featured a young Li Shimin prominently as one of its three leads .
* * The epic novel Journey to the West contains a fictional account of the Emperor's invention of the door god to protect his chamber from the spirit of a vengeful dragon whom he failed to save from execution.

Emperor Gaozong of Tang

Emperor Gaozong of Tang , personal name Li Zhi , was the third emperor of the Tang Dynasty in , ruling from 649 to 683 . Emperor Gaozong was the son of and Empress Zhangsun .

Emperor Gaozong was aided in his rule by Empress Wu during the later years of his reign after a series of strokes left him incapacitated. Emperor Gaozong delegated all matters of state to his wife and after he died in 683, power fell completely into the hands of Empress Wu, who subsequently became the first and only reigning Empress of China. After his death, he was interred at the Qianling Mausoleum along with Wu Zetian.

Historians have generally viewed Emperor Gaozong as a weak ruler, inattentive to the business of the state and leaving such business to his powerful wife Empress Wu. During the first part of his reign, Tang territorial gains, which started with his father Emperor Taizong, continued, including the conquest of Baekje, Goguryeo, and Western Tujue, but throughout the 670s, much of those gains were lost to Tufan, Silla, Khitan, and Balhae. Further, territory previously conquered that belonged to both Eastern and Western Tujue were subjected to repeated rebellions.

Background and life as Prince of Jin

Li Zhi was born in 628. He was the ninth son of his father, , and the third son of his mother, Emperor Taizong's wife Empress Zhangsun. In 631, he was created the Prince of Jin. In 633, he was made commandant of Bing Prefecture , but remained at the capital Chang'an rather than reporting to Bing Prefecture. When Empress Zhangsun died in 636, Emperor Taizong was particularly touched by the grief that Li Zhi displayed, and from that point on particularly favored him. Sometime while he was the Prince of Jin, at the recommendation of his grand aunt Princess Tong'an, he married the of Princess Tong'an's husband Wang Yu as his wife and princess.

Meanwhile, Li Zhi's two older brothers by Empress Zhangsun, Li Chengqian the Crown Prince and Li Tai the Prince of Wei, were locked in an intense rivalry, as Li Tai was favored by Emperor Taizong for his talent and was trying to displace Li Chengqian. Li Chengqian, in fear, entered into a conspiracy with the general Hou Junji, his uncle Li Yuanchang the Prince of Han, the imperial guard commander Li Anyan , and his brothers-in-law Zhao Jie and Du He to overthrow Emperor Taizong. The plot was discovered in 643, and Emperor Taizong deposed Li Chengqian. He was initially going to make Li Tai the new crown prince, but later began to believe that Li Tai's machinations were responsible for Li Chengqian's downfall. The powerful chancellor Zhangsun Wuji -- Empress Zhangsun's brother -- suggested that he make Li Zhi crown prince, a possibility that Li Tai was apprehensive about. Li Tai tried to intimidate Li Zhi, who had been friendly with Li Yuanchang, by pointing out to Li Zhi that Li Yuanchang had been part of the plot and that he should be concerned for himself. When Emperor Taizong noticed Li Zhi worrying about this and was told by Li Zhi of Li Tai's intimidation, Emperor Taizong's mind became set. He exiled Li Tai, and on April 30, 643, he created Li Zhi the new crown prince. He made Zhangsun and two other senior chancellors, Fang Xuanling and Xiao Yu, senior advisors to Li Zhi, and made another chancellor, Li Shiji, the head of Li Zhi's household. At the advice of another key official, , who pointed out that the crown prince needed to have a group of well-learned scholars that he was close to, Emperor Taizong appointed Liu, as well as Cen Wenben, Chu Suiliang, and Ma Zhou, to serve as Li Zhi's friends and advisors.

As Crown Prince

Late in 643, Emperor Taizong issued an edict to select beautiful women among good households to serve as Li Zhi's concubines. However, after Li Zhi declined such treatment, Emperor Taizong cancelled the edict. However, during his years as crown prince, he was said to have favored his concubine , having two daughters and one son with her, much to the chagrin of his wife Crown Princess Wang, who was childless and jealous for Consort Xiao. Three other concubines of his bore his other sons Li Zhong, Li Xiao , and Li Shangjin .

Around the same time, however, he also became concerned that Li Zhi, who was considered kind but weak in character, would not be strong enough to be an emperor, and secretly discussed with Zhangsun Wuji the possibility of making another son by his concubine Consort Yang , Li Ke the Prince of Wu, crown prince. Zhangsun repeatedly opposed the idea, and Emperor Taizong did not carry this out.

In 645, when Emperor Taizong launched a , he took Li Zhi with him to Ding Prefecture and then left Li Zhi there to be in charge of logistics, before heading to the front himself. He also left senior officials Gao Shilian, Liu Ji, Ma Zhou, Zhang Xingcheng, and Gao Jifu to assist Li Zhi. After the campaign ended in failure later that year, as Emperor Taizong was leading the army back from the front, Li Zhi went to meet him at Linyu Pass . Emperor Taizong suffered an injury during the campaign, and Li Zhi was said to have, as Emperor Taizong's conditions were getting worse, sucked the pus out of his wound, until Emperor Taizong recovered somewhat. In 646, with Emperor Taizong still recovering, he transferred some of the imperial authorities to Li Zhi. Li Zhi stayed at the imperial palace and attended to Emperor Taizong in his illness. That year, when Emperor Taizong was due to visit Ling Prefecture to meet with a number of tribal chiefs who were formerly vassals of Xueyantuo -- which had collapsed under Tang and Huige attacks earlier that year -- he was set to take Li Zhi with him, but at Zhang's suggestion left Li Zhi in charge at Chang'an instead, to allow Li Zhi to become more familiar with the important affairs of state in his absence. After Emperor Taizong returned from Ling Prefecture, he retained for himself the authorities over imperial worship, state guests, military, the commissioning of officers of higher than the fifth rank, and executions, and transferred all other authorities to Li Zhi.

In 647, a commoner named Duan Zhichong submitted a petition to Emperor Taizong, asking him to pass the throne to Li Zhi. Li Zhi, concerned that Emperor Taizong might be offended, was worried and grieving, and Zhangsun suggested that Duan be executed. Emperor Taizong did not take offense and did not punish Duan or Li Zhi. Meanwhile, Li Zhi began to build a Buddhist temple named Daci'en Temple in commemoration of his mother Empress Zhangsun, and the temple was completed in 648.

In 649, while at the summer palace Cuiwei Palace , Emperor Taizong was gravely ill, and he, while impressed with Li Shiji's abilities, was concerned that Li Shiji was too able and would not submit to Li Zhi. He stated to Li Zhi:

He then demoted Li Shiji to the post of the commandant of Die Prefecture . Li Shiji, realizing what was happening, after receiving the order, departed without hesitation.

As Emperor Taizong's illness was getting more serious, Li Zhi continuously attended to him and wept constantly, often going without food, which touched Emperor Taizong greatly. Emperor Taizong entrusted Li Zhi to Zhangsun and Chu Suiliang, and then died on July 10, 649. Initially, Li Zhi was so mournful that he could not carry out any actions other than holding onto the necks of Zhangsun and Chu. Zhangsun, while mourning himself, reminded Li Zhi that he was now in charge of the empire and must act accordingly. Zhangsun also ordered that Emperor Taizong's death not be announced for the time being, and then, the next day, accompanied Li Zhi back to Chang'an. Zhangsun issued several edicts in Emperor Taizong's name -- including making Yu Zhining, Zhang, and Gao Jifu chancellors. Two days later, Emperor Taizong's death was officially announced. On July 15, Li Zhi took the throne .


''Yonghui'' era

Emperor Gaozong's first move as emperor was to cancel a second campaign against Goguryeo that Emperor Taizong had planned for later 649. While Li Tai was disallowed from attending Emperor Taizong's funeral, Emperor Gaozong permitted him to again have a staff and be allowed to use wagons, clothes, and foods of high quality. Emperor Gaozong created his wife Crown Princess Wang empress and created her father Wang Renyou the Duke of Wei. It was said that early in Emperor Gaozong's reign, he greatly respected both his uncle Zhangsun Wuji and Chu Suiliang and followed their advice, and that therefore, during this part of his reign, the government was organized well and the people were comforted, much like during the reign of Emperor Taizong, although in winter 650, Chu was accused of forcibly purchasing private land and paying below-market price, and was demoted to be a prefectural prefect.

Also in 650, the general Gao Kan -- whose army had been launched by Emperor Taizong against the newly reconstituted Eastern Tujue under Chebi Khan Ashina Hubo prior to Emperor Taizong's death -- captured Ashina Hubo and brought him back to Chang'an. Emperor Gaozong spared Ashina Hubo and made him a general, putting his people directly under Tang rule. Meanwhile, with two of the Xiyu states previously conquered by Tang and governed by Tang-installed kings, Qiuzi and Yanqi in disturbance, Emperor Taizong returned their previously-captured kings, Bai Helibushibi and Long Tuqizhi respectively, to their thrones.

In 651, the Western Tujue prince , who had sought and received protection from Emperor Taizong, broke away from Tang and defeated Western Tujue's Yipishekui Khan, taking over Western Tujue himself and no longer subordinate under Tang. In fall 651, Ashina Helu attacked Tang's Ting Prefecture , and Emperor Gaozong responded by commissioning the generals Liang Jianfang and Qibi Heli to attack Ashina Helu. Liang and Qibi achieved some victories against Ashina Helu's general Zhuxie Guzhu , but then withdrew without engaging Ashina Helu.

Meanwhile, as Empress Wang was sonless, her uncle, the chancellor , suggested to her that she ask Emperor Gaozong to create his oldest son Li Zhong, whose mother Consort Liu was of low birth and therefore she considered nonthreatening, crown prince so that Li Zhong would be grateful of her in the future. Liu also persuaded Zhangsun to suggest the idea as well, and Emperor Gaozong. in fall 652, Emperor Gaozong created Li Zhong crown prince. By this point, however, Empress Wang was facing a major threat from another romantic rival. When Emperor Gaozong was crown prince, he had been attracted by the beauty of one of Emperor Taizong's concubines, . After Emperor Taizong's death, all of his concubines who did not bear sons were housed at Ganye Temple to be Buddhist nuns. In either 650 or 651, when Emperor Taizong was visiting Ganye Temple to offer incense to Buddha, when he saw Consort Wu. Both of them wept. When Empress Wang heard this, she, wanting to divert Emperor Gaozong's favor from Consort Xiao, secretly instructed Consort Wu to grow her hair back, while suggesting to Emperor Gaozong that he take her as a concubine. Consort Wu was intelligent and full of machinations, and therefore, when she first returned to the palace, she acted humbly and flattered Empress Wang, who trusted her greatly and recommended her to Emperor Gaozong. Soon, Emperor Gaozong became enamored with Consort Wu.

Meanwhile, Emperor Gaozong's sister Princess Gaoyang and her husband Fang Yi'ai , were implicated in 652 of conspiring with another brother-in-law Chai Lingwu , the general Xue Wanche and Emperor Gaozong's uncle Li Yuanjing the Prince of Jing to make Li Yuanjing emperor. Fang, knowing that Zhangsun had long been apprehensive of Li Ke, falsely implicated Li Ke in the plot as well, hoping to ingratiate Zhangsun sufficiently that he would be spared. nevertheless, in spring 653, at the suggestion of Zhangsun and Cui Dunli -- despite Emperor Gaozong's initial inclination to spare Li Yuanjing and Li Ke -- Emperor Gaozong ordered that Fang, Xue, and Chai be executed, and that Li Yuanjing, Li Ke, and the Princesses Gaoyang and Baling be forced to commit suicide. Zhangsun took this opportunity to accuse several other officials friendly with Fang or hostile to him -- the chancellor Yuwen Jie, Li Daozong the Prince of Jiangxia, and the general Zhishi Sili -- of being friendly with Fang and had them exiled. He also deposed and exiled Li Ke's mother Consort Yang and Consort Yang's other son Li Yin the Prince of Shu, as well as Fang's brother Fang Yizhi and Xue's brother Xue Wanbei .

By 654, both Empress Wang and Consort Xiao had lost favor with Emperor Gaozong, and the former romantic rivals joined forces against Consort Wu, but to no avail, and as a sign of his love to Consort Wu, in 654 he conferred posthumous honors on her father Wu Shihuo . Later that year, after Consort Wu gave birth to a daughter, Empress Wang visited her -- and after Empress Wang left, Consort Wu killed her own daughter and then implicated Empress Wang in the killing. In anger, Emperor Gaozong considered deposing Empress Wang and replacing her with Consort Wu, but wanted to make sure that the chancellors would support this, and so visited Zhangsun's house with Consort Wu, awarding him with much treasure, but when he brought up the topic that Empress Wang was sonless , Zhangsun repeatedly found ways to divert the conversation, and subsequent visits by Consort Wu's mother Lady Yang and the official Xu Jingzong, who was allied with Consort Wu, to seek support from Zhangsun were also to no avail.

In summer 655, Consort Wu accused Empress Wang and her mother Lady Liu of using witchcraft. In response, Emperor Gaozong barred Lady Liu from the palace and demoted Liu Shi. Meanwhile, a faction of officials began to form around Consort Wu, including Li Yifu, Xu, Cui Yixuan , and Yuan Gongyu . On an occasion in fall 655, Emperor Gaozong summoned the chancellors Zhangsun, Li Shiji , Yu Zhining, and Chu to the palace -- which Chu deduced to be regarding the matter of changing the empress. Li Ji claimed an illness and refused to attend. At the meeting, Chu vehemently opposed deposing Empress Wang, while Zhangsun and Yu showed their disapproval by silence. Meanwhile, other chancellors Han Yuan and Lai Ji also opposed the move, but when Emperor Gaozong asked Li Ji again, Li Ji's response was, "This is your family matter, Your Imperial Majesty. Why ask anyone else?" Emperor Gaozong therefore became resolved. He demoted Chu to be a commandant at Tan Prefecture , and then deposed both Empress Wang and Consort Xiao, putting them under arrest and creating Consort Wu empress instead to replace Empress Wang. Then, at Xu's suggestion, in spring 656, Emperor Gaozong demoted LI Zhong to be the Prince of Liang and created Empress Wu's oldest son Li Hong the Prince of Dai crown prince instead.

In 655 as well, Emperor Gaozong commissioned the general Cheng Zhijie to attack Ashina Helu, but while the campaign saw some victories over Western Tujue's substituent tribes Geluolu and Chuyue , was plagued by Cheng's inability to reign in his assistant Wang Wendu from pillaging and inappropriately halting the army, end after the campaign ended in early 657, both Cheng and Wang were deposed from their offices.

''Xianqing'' era

In 657, Emperor Gaozong commissioned the general Su Dingfang, who had served under Cheng Zhijie in the earlier failed campaign, to attack Ashina Helu, assisted by Ren Yaxiang and Xiao Siye . They were joined by the Western Tujue chieftains and , who had submitted to Tang during Emperor Taizong's reign. The campaign caught Ashina Helu by surprise, and Su defeated him in several battles, causing him to flee to the kingdom Shi , which arrested him and delivered him to Su, thus largely ending Western Tujue as an organized state.

Meanwhile, Xu Jingzong and Li Yifu, aligned with Empress Wu, began to carry out a campaign of reprisal on her behalf. In 657, they accused Han Yuan and Lai Ji of plotting treason with Chu Suiliang, who was then serving as the commandant at Gui Prefecture . Emperor Gaozong demoted Han and Lai to be prefects of distant prefectures, and demoted Chu and Liu Shi to even more distant prefectures -- in Chu's case, to the extremely distant Ai Prefecture , and Chu's subsequent petition, sent from Ai Prefecture, pleading with Emperor Gaozong, fell on deaf ears.

Empress Wu's reprisals did not end there. In 659, Zhangsun Wuji became the next target. At that time, two low level officials, Wei Jifang and Li Chao had been accused of improper associations, and when Emperor Gaozong put Xu and Xin Maojiang of investigating, Xu falsely accused Wei and Li to be part of a treasonous plot by Zhangsun. Emperor Gaozong, without meeting with Zhangsun, believed Xu, and put Zhangsun under house arrest in exile at Qian Prefecture . Xu further implicated Chu, Liu, Han, and Yu Zhining in the plot as well. Yu was removed from his post. Chu, who had died in 658, was posthumously stripped of all titles, and his sons Chu Yanfu and Chu Yanchong were executed. Orders were also issued to execute Liu and Han, although Han died before the execution order reached his location. Meanwhile, Zhangsun, once he reached his place of exile, was forced to commit suicide. It was said that after Han's and Lai's deaths, no official dared to criticize the emperor any further.

Also in 659, a vassal of Western Tujue, Duman , the commander of the Sijie Tribe , rebelled against Tang suzerainty, along with Western Tujue's subject kingdoms Shule , Zhujupo , and Yebantuo . The joint forces commanded by Duman quickly defeated the Tang vassal Yutian . In winter 659, Emperor Gaozong sent Su Dingfang against Duman, and once he arrived in the vicinity of Duman's army, he selected 10,000 infantry soldiers and 3,000 cavalry soldiers and made a surprise attack on Duman. When he arrived at Duman's headquarters, Duman was surprised, and after Su initially defeated Duman, Duman was forced to withdraw within the city. Su put the city under siege, and Duman surrendered. In spring 660, Su took Duman back to the eastern capital Luoyang, where Emperor Gaozong was at the time, to present Duman to him. Some officials requested that Duman be executed, but Su made a plea on Duman's behalf -- that he had promised Duman life before Duman surrendered -- and Emperor Gaozong stated that while under the law, Duman should die, he would honor Su's promise, and so he spared Duman.

On the other end of the Tang atmosphere of influence, on the Korean Peninsula, Baekje had been attacking the Tang vassal Silla. Once Su returned from the Sijie campaign, Emperor Gaozong commissioned him to head over the sea to attack Baekje, in conjunction with Silla. Su quickly captured the Baekje capital Sabi, forcing Baekje's and his crown prince Buyeo Yung to surrender. Emperor Gaozong ordered that Baekje be annexed as Tang territory. Emperor Gaozong then followed up by commissioning Su, along with Qibi Heli, Liu Boying , and Cheng Mingzhen , to attack Goguryeo.

''Longshuo'' and ''Linde'' eras

Meanwhile, just after Su Dingfang left Baekje territory to attack Goguryeo, the Buddhist monk Dochim/Daochen and the former Baekje general Buyeo Boksin rose to try to revive Baekje. They welcomed the Baekje prince Buyeo Pung back from Japan to serve as king, with Juryu/Zhouliu as their headquarters. They put the Tang general Liu Renyuan under siege in Sabi. Emperor Gaozong sent the general Liu Rengui, who had previously been demoted to commoner rank for offending Li Yifu, with a relief force, and Liu Rengui and Liu Renyuan were able to fight off the Baekje resistance forces' attacks, but were themselves not strong enough to quell the rebellion, and so for some time the armies were in stalemate.

Meanwhile, Su advanced on the Goguryeo capital Pyongyang and put it under siege, but was unable to capture it quickly. In spring 662, after the general Pang Xiaotai was defeated by Goguryeo forces at Salsu/She River and was killed along with his 13 sons, Su ran into harsh snowstorms and withdrew.

Around the same time, after the death of the Huige chief Yaoluoge Porun , who had been obedient to Tang, Yaoluoge Porun's nephew Yaoluoge Bisudu rose in rebellion with the Tongluo and Pugu tribes in conjunction with other Tiele Confederation tribes. Emperor Gaozong sent the general Zheng Rentai to attack the Tiele, but while Zheng was initially victorious, his officers became bogged down in pillaging and eventually suffered great losses after being caught in poor weather. Emperor Gaozong instead sent Qibi, who was ethnically Tiele, assisted by Jiang Ke, to Tiele to try to persuade them to surrender. Qibi was able to do so, and rebel leaders were arrested and turned over to Tang. Qibi executed them and ended the rebellion.

Meanwhile, for reasons unknown, also in 662 Emperor Gaozong sent the general Su Haizheng to attack Qiuzi and ordered Ashina Mishe and Ashina Buzhen to assist him. Ashina Buzhen, who had a rivalry with Ashina Mishe, falsely informed Su that Ashina Mishe was set to rebel and would attack the Tang army, and Su responded by ambushing Ashina Mishe, killing him and his chief assistants. The Western Tujue tribes, angry over Ashina Mishe's death, largely turned away from Tang and submitted to Tufan instead, and when Ashina Buzhen died later that year, Tang influence in the region was greatly reduced.

During these years, Li Yifu had been, due to favors from Emperor Gaozong and Empress Wu, exceedingly powerful, and he grew particularly corrupt. In 663, after reports of Li Yifu's corruption were made to Emperor Gaozong, Emperor Gaozong had Liu Xiangdao and Li Ji investigate, finding Li Yifu guilty. Li Yifu was removed from his post and exiled, and would never return to Chang'an.

During the years, Empress Wu had repeatedly, in her dreams, seen Empress Wang and Consort Xiao, in the states they were after their terrible deaths, and she came to believe that their spirits were after her. For that reason, Emperor Gaozong started remodeling a secondary palace, Daming Palace , into Penglai Palace , and when Penglai Palace's main hall, Hanyuan Hall , was completed in 663, Emperor Gaozong and Empress Wu moved to the newly remodeled palace .

Also in 663, Tufan attacked the Tang vassal Tuyuhun. Tuyuhun's Ledou Khan Murong Nuohebo, unable to withstand the Tufan attack, took his people and fled into Tang territory to seek protection, thus ending Tuyuhun's existence as a state.

Meanwhile, also in 663, Liu Rengui and Liu Renyuan, in conjunction with Silla's and the former Baekje crown prince Buyeo Yung, defeated Buyeo Pung and Japanese forces sent to assist him, at the Battle of Baekgang. Buyeo Pung fled to Goguryeo, ending the Baekje resistance movement. Emperor Gaozong recalled Liu Renyuan, leading Liu Rengui in charge of former Baekje territory, but in 664 sent Liu Renyuan back to Baekje and tried to recall Liu Rengui. Liu Rengui petitioned to remain to prepare for another attack on Goguryeo, and Emperor Gaozong agreed to let him remain.

By 664, Empress Wu, who felt that her power was well-established, was extending her influence further in the political arena, and when the eunuch Wang Fusheng reported to Emperor Gaozong that she had engaged the sorcerer Guo Xingzhen -- an act that was strictly forbidden -- Emperor Gaozong, in anger, summoned the chancellor Shangguan Yi to consult Shangguan. Shangguan suggested that he depose Empress Wu. He agreed, and had Shangguan draft an edict to that effect. However, Empress Wu had received information that that was happening, and she emerged to defend herself. Emperor Gaozong could not carry out the removal, and instead blamed Shangguan. As both Shangguan and Wang had previously served the former crown prince Li Zhong, Empress Wu had Xu Jingzong falsely accuse Shangguan, Wang, and Li Zhong of conspiring against Emperor Gaozong's life. Around the new year 665, Shangguan and Wang were executed, and Li Zhong was forced to commit suicide. From this point on, whenever Emperor Gaozong presided over imperial meetings, Empress Wu would sit behind a pearl screen behind him to hear the reports as well, and political power largely fell into her hands. She and Emperor Gaozong were thereafter referred to as the "Two Saints."

In 665, Emperor Gaozong went to Luoyang and began preparation in earnest to make sacrifices to heaven and earth at Mount Tai -- a traditional ceremony for emperors that were rarely carried out in history due to the large expenses associated with them. At Empress Wu's request -- as she reasoned that the sacrifice to earth also included sacrifices to past empresses , she believed that it would be more appropriate to have females offer the sacrifices rather than male officials, as had been tradition in the past. Emperor Gaozong decreed that the male ministers would offer sacrifices first, but Empress Wu would next offer sacrifices, followed by Princess Dowager Yan, the mother of Emperor Gaozong's younger brother the Prince of Yue. In winter 665, Emperor Gaozong departed Luoyang and headed for Mount Tai. On the lunar new year , he initiated the sacrifices to heaven, which were not completed until the next day. On February 12, sacrifices were made to earth. He gave general promotions to the imperial officials, and it was said that starting from this time, promotions of imperial officials, which were strict and slow during the reigns of Emperors Gaozu and Taizong, began to become more relaxed and often excessive. He also declared a general pardon, except for long-term exiles.

''Qianfeng'' and ''Zhongzhang'' eras

In summer 666, Yeon Gaesomun died and was initially succeeded as ''Mangniji'' by his oldest son Yeon Namsaeng. As Yeon Namsaeng subsequently carried out a tour of Goguryeo territory, however, rumors began to spread both that Yeon Namsaeng was going to kill his younger brothers Yeon Namgeon and Yeon Namsan, whom he had left in charge at Pyongyang, and that Yeon Namgeon and Yeon Namsan were planning to rebel against Yeon Namsaeng. When Yeon Namsaeng subsequently sent officials close to him back to Pyongyang to try to spy on the situation, Yeon Namgeon arrested them and declared himself ''Mangniji'', attacking his brother. Yeon Namsaeng sent his son to Tang to seek aid. Emperor Gaozong saw this as the opportunity to destroy Goguryeo, and he initially commissioned Qibi Heli to aid Yeon Namsaeng, and also sent the generals Pang Tongshan and Gao Kan to attack Goguryeo.

Meanwhile, Empress Wu's sister, the Lady of Han , and her daughter Lady Helan had both been frequently visiting the palace and were said to be "favored" by Emperor Gaozong. When Lady of Han died in 666, Emperor Gaozong created Lady Helan the Lady of Wei, and wanted to let her live in the palace, but hesitated because he thought Empress Wu would be jealous. When Empress Wu heard this, she was indeed jealous, and therefore she poisoned meat offered by her nephews Wu Weiliang and Wu Huaiyun , who had been on poor relations with her and whose grandmother were not her mother Lady Yang; she then gave the poisonous meat to Lady Helan, who ate it and died. Empress Wu then implicated Wu Weiliang and Wu Huaiyun in Lady Helan's death and executed them.

Around the new year 667, Emperor Gaozong further commissioned Li Ji to be the overall commander of the attack on Goguryeo, assisted by Hao Chujun. In fall 667, Li Ji crossed the Liao River and captured Xincheng . The Tang forces thereafter fought off counterattacks by Yeon Namgeon and joined forces with Yeon Namsaeng, although they were initially unable to cross the Yalu River. In spring 668, Li Ji turned his attention to Goguryeo's northern cities, capturing the important city Buyeo/Fuyu . In fall 668, he crossed the Yalu and put Pyongyang under siege. Yeon Namsan and surrendered, and while Yeon Namgeon continued to resist in the inner city, his general, the Buddhist monk Sinseong/Xincheng turned against him and surrendered the inner city to Tang forces. Yeon Namgeon tried to commit suicide, but was seized and treated. This was the end of Goguryeo, and Tang annexed Goguryeo into its territory, with Xue Rengui being put initially in charge of former Goguryeo territory as . However, there was much resistance to Tang rule , and in 669, following Emperor Gaozong’s order, a part of the Goguryeo people were forced to move to the region between the Yangtze River and the Huai River, as well as the regions south of the Qinling Mountains and west of Chang'an, only leaving old and weak inhabitants in the original land.

''Xianheng'' era

In summer 670, Tufan captured the 18 prefectures that Tang had established over the Xiyu region, and Emperor Gaozong, in response, commissioned Xue Rengui, assisted by Ashina Daozhen and Guo Daifeng , to attack the Qinghai Lake area, to try to open a second front against Tufan as well as to try to restore the territory previously held by Tuyuhun. However, Guo, who felt himself to be Xue's equal as a general, was displeased at serving as an assistant, and their discord eventually led to a major defeat by Tufan's prime minister Lun Qinling . For the time being, the Xiyu territory was lost. By 672, Emperor Gaozong gave up the hopes of reestablishing Tuyuhun and moved Murong Nuohebo and his people deep into Tang territory.

By 674, Emperor Gaozong was displeased at Silla's King Munmu's encouragement of Goguryeo revival movements who continued to resist Tang rule over the region and he stripped King Munmu of all Tang-bestowed titles, including the title of King of Silla, and conferred them on King Munmu's brother Kim Immun/Jin Renwen instead, commissioning Liu Rengui, assisted by Li Bi and the ethnically Mohe general Li Jinxing , to escort Kim Immun back to Silla territory.

''Shangyuan'' and ''Yifeng'' eras

In 675, Liu Rengui reached Silla territory, achieving victories over Silla forces, in conjunction with Mohe forces that submitted to Tang. However, after King Munmu apologized and offered tribute, Emperor Gaozong ordered a withdrawal and recalled Kim Immun.

Meanwhile, by this time, Emperor Gaozong was continuously suffering from a persistent headache, and he considered making Empress Wu regent. Both Hao Chujun and Li Yiyan objected strenuously, and Emperor Gaozong did not make her regent. However, this did not prevent Empress Wu from engaging a number of mid-level officials, including Yuan Wanqing and Liu Yizhi, known as the "North Gate Scholars" to serve as her advisors and to divert the powers of the chancellors.

Also in 675, Li Hong the Crown Prince died suddenly -- with traditional historians largely attributing his death to poisoning by Empress Wu, due to her anger that he tried to curb her power grab and had shown sympathy to his two older sisters born of Consort Xiao -- Princesses Yiyang and Gao'an. Emperor Gaozong, in grief, posthumously honored Li Hong as an emperor, and he created Empress Wu's second son, Li Xian the Prince of Yong, crown prince.

Along with the war with Silla, some resistance of Goguryeo people continued to plague Tang rule there. In 676, Emperor Gaozong withdrew Tang forces from the Korean Peninsula entirely and moved the Protectorate General to Pacify the East to Liaodong and the commandant of Xiongjin , who governed the former Baekje territory at Sabi, to Jian'an , allowing Silla to unite the Korean Peninsula. In 677, he bestowed on Goguryeo's former King Bojang, Go Jang, the titles of Prince of Chaoxian and commandant of Liaodong, giving him the forcibly removed Goguryeo people. He also bestowed on Buyeo Yung the title of Prince of Daifang and commandant of Xiongjin -- with the intent of letting Go Jang and Buyeo Yung to rebuild Goguryeo and Baekje as loyal vassals to counteract Silla. To accommodate these movements, the Protectorate General was further moved to Xincheng.

Meanwhile, Tang had to endure multiple attacks from Tufan, and in 677, he commissioned Liu Rengui, then a chancellor, to take up defense position at Taohe Base , to prepare a counterattack against Tufan. However, Liu's proposals were repeatedly blocked by another chancellor, Li Jingxuan. In order to retaliate against Li Jingxuan, even though Liu knew that Li Jingxuan was not capable in military matters, he nevertheless recommended that Li Jingxuan take over for himself, and despite Li Jingxuan's attempt to decline, Emperor Gaozong commissioned Li Jingxuan to command the army against Tufan. In fall 678, Li Jingxuan's forces engaged Tufan forces commanded by Lun Qinling, and was soundly defeated, with Li Jingxuan's assistant Liu Shenli captured by Tufan. Li Jingxuan was only able to escape after being protected by the ethnically Baekje general Heichi Changzhi.

''Tiaolu'', ''Yonglong'', ''Kaiyao'', ''Yongchun'', and ''Hongdao'' eras

Meanwhile, the Western Tujue chieftain Ashina Duzhi had claimed the title of Shixing Khan and was allied with another chieftain, Li Zhefu , and they pillaged Anxi . Emperor Gaozong was ready to commission an army against Ashina Duzhi and Li Zhefu, but the official Pei Jingxian , who had previously served as secretary general at Xi Prefecture , opposed -- instead proposing that a small detachment be announced to escort the Persian prince Narsieh back to Persia to contend for regal title. Emperor Gaozong agreed and put Pei in charge of the detachment. When Pei arrived at Xi Prefecture, he, under the guise of a hunting party, summoned a number of tribal chiefs loyal to Tang in the area, and once they arrived, launched a surprise attack on Ashina Duzhi, who, caught by surprise, was forced to surrender; Li Zhefu then surrendered as well.

Meanwhile, though, another trouble was flaring up for Tang. The former Eastern Tujue territory, over which Tang had established 24 prefectures with the tribal chiefs serving as prefects, rebelled, and, under the leadership of Ashide Wenfu and Ashide Fengzhi , supported Ashina Nishoufu as khan. Emperor Gaozong sent Xiao Siye to attack Ashina Nishoufu, but after Xiao achieved a few victories, he became careless, and a counterattack by Ashina Nishoufu crushed him, advancing as far as Ding Prefecture. Ashina Nishoufu also encouraged the Xi and the Khitan to attack Ying Prefecture , although those attacks were fought off. Around the new year 680, after Pei returned from the Western Tujue front, Emperor Gaozong commissioned him to attack the Eastern Tujue. Pei defeated and captured Ashide Fengzhi, and Ashina Nishoufu's subordinates killed him and surrendered, ending the rebellion.

Meanwhile, Li Xian's relationship with Empress Wu was deteriorating, as Li Xian heard rumors that he was not born of Empress Wu but her sister Lady of Han, and was fearful. Meanwhile, earlier, Ming Chongyan , a sorcerer trusted by Empress Wu and Emperor Gaozong, had repeatedly stated that he believed Li Xian did not have the abilities to be emperor, that his younger brother the Prince of Ying had an appearance like Emperor Taizong, and that another younger brother, the Prince of Xiang, had the most honored appearance of all. Knowing that Li Xian was fearful of her, Empress Wu had the North Gate Scholars author teachings on filial piety to give to Li Xian, and also personally rebuked him, further causing him to be alarmed. When Ming was assassinated in 679, Empress Wu suspected Li Xian of carrying out the assassination. She had a report made to Emperor Gaozong that accused Li Xian of assassinating Ming. When the officials Xue Yuanchao, Pei Yan, and Gao Zhizhou were put in charge of investigations, they discovered a number of armors in Li Xian's palace. Empress Wu thus accused Li Xian of treason, and while Emperor Gaozong initially wanted to take no actions against Li Xian, at Empress Wu's insistence he relented. In fall 680, he reduced Li Xian to commoner rank, and created Li Zhe as the new crown prince.

In 681, the Eastern Tujue territory flared up again, as the chieftain Ashina Fu'nian claimed khan title and allied with Ashide Wenfu to attack Chinese territory. Emperor Gaozong again commissioned Pei to attack Eastern Tujue forces. Pei's assistant Cao Huaishun was initially defeated by Ashina Fu'nian, but after Pei sent spies to spread rumors, the rumors led to discord between Ashina Fu'nian and Ashide Wenfu. When Pei's forces approached Ashina Fu'nian's position, Ashina Fu'nian arrested Ashide Wenfu and surrendered.

In 682, the Western Tujue chieftain Ashina Chebo rebelled against Tang rule, and Emperor Gaozong initially was to commission Pei again, but before the army could depart, Pei died. However, the commandant at Anxi, Wang Fangyi was able to defeat Ashina Chebo and crush the rebellion.

Also in 682, the Eastern Tujue chief Ashina Gudulu rose, in alliance with Ashide Yuanzhen , to claim khan title. This, unlike the several earlier rebellions, actually saw the Eastern Tujue khanate being permanently reestablished to Tang's north and persisting for decades, and would plague the last two years of Emperor Gaozong's reign as well as the reigns of his successors.

Late in 683, Emperor Gaozong was seriously ill, and he, who was then at Luoyang, summoned Li Zhe, then in charge of Chang'an, to Luoyang to attend to him. On December 27, 683, he died. Li Zhe succeeded him , but actual power would be in the hands of Empress Wu, who became empress dowager.

References in Islamic sources

Known by Islamic sources as Yung Wei, which was in fact the name of the first era in his reign , Islamic sources credit him with building the first mosque, a mosque that still stands in Guangzhou. According to those records, Islam was introduced to China and Emperor Gaozong by the visit of Sa`d ibn Abi Waqqas, a companion of Muhammad, in the year 650. According to these sources, Emperor Gaozong is said to have respected the teachings of Islam greatly, feeling the teachings were compatible with Confucianism, and offered the building of the mosque as a sign of admiration. The emperor himself did not convert as he felt Islam was too restrictive for his own preferences, but according to those sources, did not stop him from allowing Sa`d and his company to spread the teachings throughout the region. These sources, however, were not corroborated by Chinese records.

Era names

* ''Yonghui'' 650-656
* ''Xianqing'' 656-661
* ''Longshuo'' 661-663
* ''Linde'' 664-666
* ''Qianfeng'' 666-668
* ''Zongzhang'' 668-670
* ''Xianheng'' 670-674
* ''Shangyuan'' 674-676
* ''Yifeng'' 676-679
* ''Tiaolu'' 679-680
* ''Yonglong'' 680-681
* ''Kaiyao'' 681-682
* ''Yongchun'' 682-683
* ''Hongdao'' 683

Chancellors during reign

* Zhangsun Wuji
* Chu Suiliang
* Xu Jingzong
* Gao Jifu
* Zhang Xingcheng
* Yu Zhining
* Yuwen Jie
* Han Yuan
* Lai Ji
* Cui Dunli
* Li Yifu
* Du Zhenglun
* Xin Maojiang
* Xu Yushi
* Ren Yaxiang
* Lu Chengqing
* Shangguan Yi
* Liu Xiangdao
* Dou Dexuan
* Le Yanwei
* Sun Chuyue
* Jiang Ke
* Lu Dunxin
* Liu Rengui
* Yang Hongwu
* Dai Zhide
* Li Anqi
* Zhao Renben
* Zhang Wenguan
* Yan Liben
* Li Jingxuan
* Hao Chujun
* Lai Heng
* Xue Yuanchao
* Li Yiyan
* Gao Zhizhou
* Zhang Da'an
* Wang Dezhen
* Pei Yan
* Cui Zhiwen
* Guo Daiju
* Cen Changqian
* Guo Zhengyi
* Wei Xuantong
* Liu Jingxian

Personal information

* Father
** Emperor Taizong of Tang
* Mother
** Empress Zhangsun
* Wives
** , mother of Crown Princes Hong, Xián, and Zhe, Prince Dan, Princess Taiping, and unnamed princess
* Major Concubines
** , mother of Prince Sujie and Princesses Yiyang and Xuancheng
** Consort Liu, mother of Crown Prince Zhong
** Consort Zheng, mother of Prince Xiao
** Consort Yang, mother of Prince Shangjin
* Children
** Li Zhong , originally the Prince of Chen , later the Crown Prince , later demoted to Prince of Liang , later demoted to commoner rank
** Li Xiao , Prince Dao of Xu , later posthumously honored as Prince Dao of Yuan
** Li Shangjin , originally the Prince of Qi , later the Prince of Bi , later the Prince of Ze
** Li Sujie , originally the Prince of Yong , later the Prince of Xun , demoted to Prince of Poyang , later the Prince of Ge , later the Prince of Xu
** Li Hong , originally the Prince of Dai , later the Crown Prince , posthumously honored Emperor Xiaojing with the temple name Yizong
** , name changed to Li De 672, changed back to Li Xián 674), originally the Prince of Lu , later the Prince of Pei , later the Prince of Yong , later the Crown Prince , later demoted to commoner rank , posthumously initially honored the Prince of Yong, later honored Crown Prince Zhanghuai
** Li Xiǎn , name changed to Li Zhe 677, changed back to Li Xiǎn 698, changed to Wu Xian 700, changed back to Li Xian 705, initially the Prince of Zhou , later the Prince of Ying , later the Crown Prince , later Emperor Zhongzong of Tang , later demoted to Prince of Luling , later the Crown Prince , later emperor again
** Li Dan , né Li Xulun , name changed to Li Lun 669, changed again to Li Dan 678, changed again to Wu Lun 690, changed again to Wu Dan 698, changed back to Li Dan 705, originally the Prince of Yin , later the Prince of Yu , later the Prince of Ji , later the Prince of Xiang , later the Prince of Yu , later Emperor Ruizong of Tang , later demoted to Crown Prince , later demoted to Prince of Xiang , later emperor again
** Unnamed princess
** Princess Yiyang
** Princess Xuancheng, later Princess Gao'an
** Princess Taiping