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.