Xinjiang has had a turbulent history. Some of the earliest known inhabitants, from c.4,000 years ago, have been found mummified in the region's deserts and appear to be of Caucasoid origin, possibly ancient Tokharians. Xinjiang first passed under Chinese rule in the 1st cent. B.C., when the emperor Wu Ti sent a Chinese army to defeat the Huns and occupy the region. In the 2d cent. A.D., China lost Xinjiang to the Uzbek Confederation but reoccupied it in the mid-7th cent. It was conquered (8th cent.) by the Tibetans, overrun by the Uigurs, who established a kingdom there, and subsequently invaded (10th cent.) by the Arabs. Xinjiang passed to the Mongols in the 13th cent. An anarchic period followed until the Manchus established (1756) loose control.
The subsequent relations between China and Xinjiang were marked by cultural and religious conflict, bloody rebellions, and tribal dissensions. In the 19th cent., this unrest was encouraged by Great Britain and czarist Russia to protect India and Siberia, respectively. Xinjiang became a Chinese province in 1881, but even as late as the establishment of the Chinese republic in 1912 it remained more or less independent of the central government. Rebellions in 1936, 1937, and 1944 further eased Chinese rule.
Late in 1949, Xinjiang capitulated to the Chinese Communists without a struggle, but there was a Uigur uprising in Hotan in 1954. On the basis of the 1953 census, which showed the Uigurs to comprise 74% of the population, Xinjiang prov. was reconstituted (1955) an autonomous region. Autonomous districts were created as well for the Kazakhs, Mongols, Hui, and Kyrgyz. In the 1950s and 1960s, the central government sent massive numbers of Chinese to Xinjiang to help develop water-conservancy and mineral-exploitation schemes. This has drastically altered the population balance, and the Chinese are approaching numerical parity with the Uigurs. National defense has also been a consideration in the strategic and sensitive region. In 1969, frontier incidents led to fighting between Soviet and Chinese forces along the border.
In the 1990s, the Turkic peoples of Xinjiang grew increasingly discontented with Chinese rule, in part because of the migration of large numbers of Chinese to the area as a result of government resettlement programs, and rioting by proindependence Muslims broke out in 1997. China subsequently increased the number of troops in the region, and has instituted a harsh crackdown on political dissent and Turkic separatists. Orthodox Islamic practices have been discouraged or suppressed by the government for fear that they will become a focus of Uigur nationalism. Occasional anti-Chinese protests and ethnic riots have occurred since 1997, most violently in 2009 (when Uigurs and Chinese attacked each other in the streets), and there also have been separatist attacks on government officials and buildings and other targets.