Xinjiang has been part of China since ancient times. The Uygurs, together with other ethnic groups, have opened up the region and have had very close economic and cultural ties with people in other parts of the country, particularly central China.
Xinjiang was called simply "Western Region" in ancient times. The Jiaohe ruins, Gaochang ruins, Yangqi Mansion of "A Thousand Houses," Baicheng (Bay) Kizil Thousand Buddha Grottoes, Bozklik Grottoes in Turpan, Kumtula Grottoes in Kuqa and Astana Tombs in Turpan all contain a great wealth of relics from the Western and Eastern Han dynasties (206 B.C. -- A.D.220). They bear witness to the efforts of the Uygurs and other ethnic groups in Xinjiang in developing China and its culture.
Zhang Qian, who lived in the second century B.C., went to the Western Region as an official envoy in 138 and 119 B.C., further strengthening ties between China and central Asia via the "Silk Road." In 60 B.C., Emperor Xuan Di of the Western Han Dynasty established the Office of Governor of the Western Region to supervise the "36 states" north and south of the Tianshan Mountains with the westernmost border running through areas east and south of Lake Balkhash and the Pamirs.