Uyghurs
Contemporary scholars consider modern Uyghurs to be the descendants of a number of people, including the ancient Uyghurs of Mongolia who arrived at the Tarim Basin after the fall of the Uyghur Khaganate, Iranic Saka tribes, and other Indo-European peoples who inhabited the Tarim Basin before the arrival of the Turkic Uyghurs. DNA analyses indicate that the peoples of central Asia such as the Uyghurs are all mixed Caucasian and East Asian. Uyghur activists identify with the Tarim mummies, remains of an ancient people who inhabited the region, but research into the genetics of ancient Tarim mummies and their links with modern Uyghurs remains problematic, both to Chinese government officials concerned with ethnic separatism, and to Uyghur activists concerned that the research could affect their people's claim of being indigenous to the region.
Yugur
The Turkic-speaking Yugurs are considered to be the descendants of a group of Uyghurs who fled from Mongolia southwards to Gansu after the collapse of the Uyghur Khaganate in 840, where they established the prosperous Gansu Uyghur Kingdom (Ganzhou Uyghur Khanate) (870-1036) with capital near present Zhangye at the base of the Qilian Mountains in the valley of the Ruo Shui. The population of this kingdom, estimated at 300,000 in Song chronicles, practised Manichaeism and Buddhism in numerous temples throughout the country.