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.
Uyghurs in Kazakhstan
By 1897, there were already roughly 56,000 Uyghurs in what is today Kazakhstan, according to the Russian Empire Census. In the 1940s, high-ranking Communist Party officials in the Kazakh SSR planned to create an Uyghur autonomous oblast in a large part of the territory of modern-day Almaty Province. However, as the intention of the government was to bring Xinjiang further into the Soviet orbit rather than afford local Uyghurs genuine autonomy, the plan was scrapped after the Communist victory in China in 1949. During the 1950s in China, ethnic tensions and repression of minority separatist movements led to a mass exodus from Xinjiang to the Kazakh SSR, consisting of Uyghurs, Kazakhs, Mongols, and Kyrgyz. Following the Sino-Soviet split and border conflict, the Chinese government closed the Xinjiang–Kazakh SSR border, both to prevent flight by ethnic minorities, and to prevent the penetration of Soviet secret agents into China.