Wuwei, Gansu
In fall 634, Emperor Taizong sent the generals Duan Zhixuan (段志玄) and Fan Xing (樊興) to attack Tuyuhun with Tang forces, supplemented by soldiers from the Qibi (契苾) and Dangxiang tribes. When Duan began the attack, however, after minor successes, Tuyuhun forces simply began to elude him and refuse to engage him. Apparently immediately after he withdrew, Tuyuhun forces again attacked Liang Prefecture (涼州, roughly modern Wuwei, Gansu).