Emperor Taizong of Tang (r. 626-649), the second emperor of the Chinese Tang Dynasty, throughout most of his reign, faces challenges from Tang's western neighbor, the state of Tuyuhun, whose Busabuo Khan Murong Fuyun constantly challenges Chinese authority in the border regions.

In 634, Emperor Taizong launches a major attack, commanded by the major general Li Jing, against Tuyuhun, dealing Tuyuhun forces heavy defeats and causing Murong Fuyun's subordinates to assassinate him in 635.

Tuyuhun, thus weakened, no longer remains a major power in the region, and while Tang, ironically, plays the role of protector for Murong Fuyun's son, the Gandou Khan Murong Shun, and grandson, the Ledou Khan Murong Nuohebo, Tuyuhun will never be able to recover, particularly with its southwestern neighbor Tufan constantly attacking it.

By 672, during the reign of Emperor Taizong's son Emperor Gaozong of Tang, Tang will be forced to move Tuyuhun remnants into its own territory, ending Tuyuhun.