Tsewang Rabtan's brother Tseren Dondup invaded the Khoshut Khanate in 1717, deposed Yeshe Gyatso, killed Lha-bzang Khan, and looted Lhasa. The Kangxi Emperor retaliated in 1718, but his military expedition was annihilated by the Dzungars in the Battle of the Salween River, not far from Lhasa. A second and larger expedition sent by Kangxi expelled the Dzungars from Tibet in 1720. They brought Kälzang Gyatso with them from Kumbum to Lhasa and installed him as the 7th Dalai Lama in 1721. The people of Turpan and Pichan took advantage of the situation to rebel under a local chief, Amin Khoja, and defected to the Qing dynasty.