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.
History of Mongolia
The Uyghurs, who were subjects to the Göktürks, revolted in 745 and founded the Uyghur Khaganate which replaced the Eastern Turkic Khaganate. The Uyghur kagan Bayanchur established Ordu-Baliq City on the Orkhon river in 751. The Tang Empire invited the Uyghurs to subdue the An Lushan rebellion in 755. Successful campaigns of the Uyghur Khaganate led to a peace with the Tang dynasty of China which paid compensation for the suppression of An in silk and grain for 12 years after 766.
Though a faction of the Uyghurs were Buddhists, the Manichaeism became the official religion of the Khaganate in the 8th century. Nevertheless, the majority of the Uyghurs remained shamanists. The culture and economy of the Uyghur Kaganate were more advanced than those of its predecessors. The Uyghurs used a 12-month calendar and calculated the dates of solar and lunar eclipses. The Uyghurs developed their own writing system based on the Sogdian script. The Tang dynasty surreptitiously encouraged the Yenisei Kirghiz and the Karluks to attack the Uyghurs and the Uyghur Khaganate fell under an invasion of the Yenisei Kirghiz in 840.