Tibetan Empire - Reign of Trisong Detsän (756–797 or 804)

Reign of Trisong Detsän (756–797 or 804)

In 756 prince Song Detsän was crowned Emperor with the name Trisong Detsän (Khri sron lde brtsan) and took control of the government when he attained his majority at 13 years of age (14 by Western reckoning) after a one-year interregnum during which there was no emperor.

In 755 China had been greatly weakened by the An Shi Rebellion, which would last until 763. In contrast, Trisong Detsän's reign was characterized by the reassertion of Tibetan influence in Central Asia. Early in his reign regions to the West of Tibet paid homage to the Tibetan court. From that time onward the Tibetans pressed into the territory of the Tang emperors, reaching the Chinese capital Chang'an (modern Xian) in late 763. Tibetan troops occupied Chang'an for fifteen days and installed a puppet emperor while Emperor Daizong was in Luoyang. Nanzhao (in Yunnan and neighbouring regions) remained under Tibetan control from 750 to 794, when they turned on their Tibetan overlords and helped the Chinese inflict a serious defeat on the Tibetans.

In 785, Wei Kao, a Chinese serving as an official in Shuh repulsed Tibetan invasions of the area.

In the meantime, the Kyrgyz negotiated an agreement of friendship with Tibet and other powers to allow free trade in the region. An attempt at a peace treaty between Tibet and China was made in 787, but hostilities were to last until the Sino-Tibetan treaty of 821 was inscribed in Lhasa in 823 (see below). At the same time, the Uyghurs, nominal allies of the Tang emperors, continued to make difficulties along Tibet's Northern border. Toward the end of this king's reign Uyghur victories in the North caused the Tibetans to lose a number of their allies in the Southeast.

Recent historical research indicates the presence of Christianity in as early as the sixth and seventh centuries, a period when the Hephthalites had extensive links with the Tibetans. A strong presence existed by the eighth century when Patriarch Timothy I (727-823) in 782 calls the Tibetans one of the more significant communities of the eastern church and wrote of the need to appoint another bishop in ca. 794.

There is a stone pillar (now blocked off from the public), the Lhasa Shöl rdo-rings, Doring Chima or Lhasa Zhol Pillar, in the ancient village of Shöl in front of the Potala in Lhasa, dating to c. 764 CE during Trisong Detsen's reign. It also contains an account of the conquest of large swathes of northwestern China including the capture of Chang'an, the Chinese capital, for a short period in 763 CE, during the reign of Emperor Daizong.