The Western Turks provided their ally Karakhoja with soldiers, but the army retreated when the Tang forces arrived.

[1] The kingdom was heavily influenced by Chinese culture and was the closest of the Tarim Basin oasis states to Tang China.

Karakhoja had been ruled since 498 by the Qu royal family, who governed the state as the most sinicized of the Tarim Basin kingdoms.

[1] The Tu-lu Qaghan, who had risen to power in 638, offered Karakhoja the military protection of the Western Turkic Khaganate.

With the support of the Western Turks, Karakhoja halted the Silk Road trade route that connected Tang China with Central Asia.