Early in the seventh century, the powerful Tang Dynasty was founded in the Central Plains, ending the disintegration and chaotic situation that and prevailed in the region for more than 300 years. At the same time, Tubo leader Songtsan Gambo welded together more than 10 separate tribes and established the Tubjo Kingdom covering a large part of what later became known as Tibet. He twice sent ministers to the Tang court requesting a member of the imperial family be given to him in marriage, and in 641, Princess Wencheng, a member of Emperor Taizong’s family, was chosen for this role. During the reign of Songtsan Gambo, political, economic and cultural relations between the two nations became increasingly friendly and extensive. This pattern of friendly relations was carried on during the next 200 years or more.

In 821, then Tubo King Tri Ralpachen dispatched envoys to Chang’an, capital of the Tang Dynasty for three times, asking for alignment. Muzong, then Emperor of the Tang Dynasty, appointed his senior officials to hold a grand alignment ceremony in the western suburb of Chang’an. In the next year, the Tang Dynasty and the Tubo Kingdom formally concluded their alliance pact in the eastern suburb of Lhasa. The two sides of the alliance reiterated their close relations bound by marriage and decided to treat each other as a member of one family. The alignment was recorded on three Tang-Tubo Peace Pledgement Monuments, one of which still stands in front of the Jokhang Monastery in Lhasa.

In 842, the Tubo Kingdom broke up, and rival groups of ministers, members of the royal family land various tribes plunged into internecine struggle that was to last in varying levels of intensity for the next 400 years. Reeling under the detrimental impact of such activities on their economic and cultural development, people on the Tibetan Plains to someday come to their rescue, Those who could no longer stand the bitterness fled to areas in present-day Gansu, Qinghai, Sichuan and Yunnan provinces.