Hou Junji
On 19 September 640 Hou Junji of Tang conquered Gaochang and set up Xi Prefecture (西州) in its place. Xi Prefecture became the seat of the Anxi Protectorate on 11 October. Qiao Shiwang became the first protector general of the Anxi and served from 640 to 642. Guo Xiaoke received the next post and served from 640 to 648. By 644 Karasahr was also conquered, and was known to the Chinese as Yanqi. Aksu (Gumo) was garrisoned by Tang troops.