The Tibetan kingdom was centered on the Tibetan Plateau, formed as a result of imperial expansion under the Yarlung dynasty heralded by its 33rd king, Songtsen Gampo, in the 7th century.
The empire further expanded under the 38th king, Trisong Detsen.
The 821–823 treaty concluded between the Tibetan Empire and the Tang dynasty delineated the former as being in possession of an area larger than the Tibetan Plateau, stretching east to Chang'an, west beyond .