 It has long been claimed that the conquest of Kucha established Tang rule over the entire Tarim Basin.This is in part due to a number of inaccurate Chinese sources linking the expedition to the establishment of the Four Garrisons of Anxi , which comprised Kucha , Karasahr , Khotan , and Kashgar . However , Zhang Guangda has used excavated texts from Gaochang ( Karakhoja or Turfan ) to show that the Tang abandoned the attempt to move the headquarters of the Protectorate of the Pacified West to Kucha after Guo Xiaoke 's assassination . Instead the headquarters returned to Gaochang until 658 , when it was moved back to Kucha following a Tang army 's suppression of a local pro @-@ Turk revolt against Haripushpa ( who died from an illness during the revolt ) . The Tang only gained a loose suzerainty over the Tarim Basin states in 649 , and did not establish military garrisons in the Tarim Basin . Most of the Tarim Basin states transferred their vassalage to the new Western Turk qaghan , Ashina Helu , in 651 , reflecting the fact that they regarded the Western Turks as their traditional overlords . The establishment of the Four Garrisons , and with them a formal Tang military protectorate over the Tarim Basin , should be dated to 658 ( after Ashina Helu 's defeat ) or even to 660 , since Kashgar remained allied with the Western Turk leader Duman until Duman 's defeat in later 659 . 
