History of the Uyghur people
The history of the Uyghur people, as with the ethnic origin of the people, is an issue of contention between Uyghur nationalists and the Chinese authority. Uyghur historians viewed the Uyghurs as the original inhabitants of Xinjiang with a long history. Uyghur politician and historian Muhemmed Imin Bughra wrote in his book "A history of East Turkestan", stressing the Turkic aspects of his people, that the Turks have a 9000-year history, while historian Turgun Almas incorporated discoveries of Tarim mummies to conclude that Uyghurs have over 6400 years of history, and the World Uyghur Congress claimed a 4,000-year history. Chinese historians however generally traced the origin of the Uyghurs to the Tiele, some to the Dingling as well as other people mentioned in ancient Chinese texts such as the Guifang. Official Chinese view asserts the Uyghurs to be of Tiele origin, and only became the main social and political force in Xinjiang during the ninth century when they migrated to Xinjiang from Mongolia after the collapse of the Uyghur Khaganate, replacing the Han Chinese that they claimed were there since the Han Dynasty. Many modern Western scholars however do not consider the modern Uyghurs to be of direct linear descent from the old Uyghur Khaganate of Mongolia, rather they are descendants of a number of people, of which the ancient Uyghurs are but one.
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.