Key Facts
- Duration
- 618–842 AD
- Founded by
- Songtsen Gampo, 33rd Yarlung king
- Tang–Tibet Treaty
- 783 AD, borders defined with Tang dynasty
- Extent at peak
- Tarim Basin to Bengal, Pamirs to Sichuan
- Religion adopted
- Buddhism introduced under Songtsen Gampo
Imperial Zenith Metrics
Historical Trajectory
Phase I: Rise
The Tibetan Empire emerged in the 7th century under Songtsen Gampo, the 33rd king of the Yarlung dynasty, who unified the Tibetan Plateau and shifted the capital to Lhasa. Military expansion extended Tibetan power into neighboring regions, while Songtsen Gampo's conversion to Buddhism and patronage of script development laid cultural foundations. The Yarlung dynasty, rooted in the Yarlung Valley since 127 BC, thus transformed from a regional lineage into an imperial power.
Phase II: Zenith
Under Trisong Detsen, the empire expanded significantly, briefly capturing the Tang capital Chang'an in 763 AD, and a formal border treaty with Tang China was concluded in 783. Tritsuk Detsen oversaw the empire at its greatest extent, stretching from the Tarim Basin and Pamirs in the west to Sichuan, Gansu, and Yunnan in the east, and south into Bengal. Buddhism was institutionalized, with Guru Padmasambhava establishing Vajrayana traditions and Samye Monastery founded as a center of learning.
Phase III: Decline
The empire's dissolution began with the murder of Tritsuk Detsen in 838 by his brother Langdarma, whose persecution of Tibetan Buddhism—particularly targeting Nyingma monasteries—destabilized imperial cohesion. Langdarma's own assassination in 842 removed the last central authority. Regional tensions between Bön adherents, old noble families, and Buddhist factions, compounded by the empire's geographic vastness, caused fragmentation into semi-autonomous chieftaincies and minor kingdoms that persisted as independent polities.
Notable Imperial Reigns
Selected rulers mapping the empire’s trajectory