The Battle of Dafei River was fought in mid-670 between the forces of the Chinese Tang dynasty and the Tibetan Empire, for control over the Tarim Basin. In 669, the Tibetan Empire invaded and conquered the Tuyuhun kingdom of Qinghai, which was a tributary state and important ally to Tang dynasty. To help Tuyuhun restore the regime, Emperor Gaozong of Tang launched the campaign against Tibet. The Chinese general, Xue Rengui, commanded a huge army of allegedly 100,000 men. He left his slower-moving baggage train and 20,000 soldiers under Guo Daifeng behind and advanced with the rest to the Qinghai Lake. The Tibetans attacked and captured the Chinese baggage train, and proceeded to destroy Xue's own army at the Dafei River. In the aftermath of the battle, Chinese control over the Tarim Basin collapsed.