Trisong Detsen

Trisong Detsen (Tibetan: ཁྲི་སྲོང་ལྡེ་བཙན, Wylie: khri srong lde brtsan) was the 38th King (Tsenpo) of Tibet from 755 to 797, succeeding his father Tridé Tsuktsen. He was the second of the "Three Dharma Kings of Tibet" — Songtsen Gampo, Trisong Detsen, Ralpachen — honored for their pivotal roles in the introduction of Buddhism to Tibet and the establishment of the Nyingma school of Tibetan Buddhism. Sowa Rigpa or Traditional Tibetan medicine was developed during his reign.

Trisong Detsen became one of Tibet's greatest kings during its empire era, and an unparalleled Buddhist benefactor to Guru Padmasambhava, to Khenpo Shantarakshita, to his court, and to the founding of the Vajrayana. By the end of his reign, he grew the extent of the Tibetan Empire beyond their previous borders, reset the borders between Tibet and the Tang dynasty in 783, and even shortly occupied the Tang capital at Chang'an in 763, where he installed an emperor.

This was a reverse to an earlier trend Trisong Detsen inherited whereby the empire briefly declined somewhat from its extent under Songtsen Gampo, the founder of the empire. Some disintegration continued when, in 694, Tibet lost control of several cities in Turkestan and in 703, kingdoms in Nepal broke into rebellion while Arab forces had vied for influence along the western borderlands of the Tibetan Empire.