Uyghurs
The history of the Uyghur people, as with the ethnic origin of the people, is a matter 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 Turghun 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 in East Turkestan. However, the official Chinese view asserts that the Uyghurs in Xinjiang originated from the Tiele tribes 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 they claimed were there since the Han Dynasty. Many contemporary Western scholars, however, do not consider the modern Uyghurs to be of direct linear descent from the old Uyghur Khaganate of Mongolia. Rather, they consider them to be descendants of a number of peoples, one of them the ancient Uyghurs.
Turkmens
The modern Turkmen people descend, at least in part, from the Oghuz Turks of Transoxiana, the western portion of Turkestan, a region that largely corresponds to much of Central Asia as far east as Xinjiang. Oghuz tribes had moved westward from the Altay mountains in the 7th century AD, through the Siberian steppes, and settled in this region. They also penetrated as far west as the Volga basin and the Balkans. These early Turkmens are believed to have mixed with native Sogdian peoples and lived as pastoral nomads until the Russian invasion of the 19th century.