Tocharian languages
The collapse of the Uyghur Khaganate in 840 AD led to the movement of the Uyghurs south to Turpan and Gansu, and some absorbed by the Karluks. Tocharian languages became extinct due to Uyghur migrations to these areas. The Uyghurs of Turfan (or Qocho) became Buddhists. In the tenth century, the Karluks, Yagmas, Chigils and other Turkic tribes founded the Kara-Khanid Khanate in Semirechye, Western Tian Shan, and Kashgaria.