In the
early Tang Dynasty, the population in Hequ (River Turning) area covered seven groups in
ethnic composition. They were
Han, Jihu, Turk, Tiele, Zhaowu, Tangut and Tuyuhun. Their population and distribution varied with different times and locations. In 646 AD, the total population in Hequ amounted tosome 180,000. The Han and Jihu, approximately 50,000 in population, were distributed in marginal areas of Hequ, the Turk practiced nomadism in the two prefectures of Xiazhou and Shengzhou in the east Hequ as well as in the northwest Hequ, and the Zhaowu stayed in the west Hequ, between Yanzhou and Xiazhou. Later on, new changes occurred in their population and distribution due to the immigration of the Tuyuhun, Tangut and Tiele. By 742 AD, the total population in Hequ had amounted to 750,137. After the armed rebellion led by An Lushan and Shi Siming, the Tiele, Turk, Zhaowu and Tuyuhun moved away from Hequ one after another, but the Han, Jihu and Tangut remained there. Moreover, the population of the Tangut increased noticeably, and their range of distribution enlarged continuously, covering all the area. In this way, they became the main part of the local population.