Tang dependence upon their northern allies is apparently a source of embarrassment to the Chinese, who surreptitiously encourage the Kyrgyz and the Karluks to attack the Uyghurs, driving them south into the Tarim Basin.

As a result of the Kyrgyz action, the Uyghur empire collapses in 846.

Some of the Uighurs emigrate to Chinese Turkestan (the Turpan region), where they establish a flourishing kingdom that will freely submit to Genghis Khan several centuries later.

Ironically, this weakening of the Uighurs undoubtedly hastens the decline and fall of the Tang Dynasty over the next fifty years.