Lanzhou is the capital and largest city of Gansu Province in Northwest China. A prefecture-level city, it is a key regional transportation hub, allowing areas further west to maintain railroad connections to the eastern half of the country. Lanzhou is home to 3,616,163 inhabitants at the 2010 census and 2,177,130 in the built-up area (urban) on 1,088 sq km. Originally in the territory of the Western Qiang peoples, Lanzhou became part of the territory of Qin (sta) in the 6th century BC. In 81 BC, under the Han dynasty (206 BC-220 AD), it was taken from the Huns' Huandi Chanyu and made the seat of Jincheng commandery, and later of the Jincheng county (xian), later renamed Yunwu.