separate province in 1666, Lanzhou became its capital.
In 1739 the seat of Lintao was transferred to Lanzhou, which was later made a superior prefecture called Lanzhou.
Lanzhou was badly damaged during the Dungan revolt in 1864–1875. In the 1920s and 1930s it became a center of Soviet influence in northwestern China. During the Second Sino-Japanese War (1937–1945) Lanzhou, linked with Xi'an by highway in 1935, became the terminus of the 3,200 km (2,000 mi) Chinese-Soviet highway, used as a route for Soviet supplies destined for the Xi'an area. This highway remained the primary traffic route of northwestern China until the completion of the railway from Lanzhou to Urumqi, Xinjiang. During the war Lanzhou was heavily bombed by the Japanese.
During the 1937 Japanese invasion of China, the Guominjun Muslim Generals Ma Hongkui and Ma Bufang protected Lanzhou with their cavalry troops, putting up such resistance that the Japanese never captured Lanzhou.
The city is the seat of a currently vacant Roman Catholic diocese and was previously the center of a vicariate apostolic (Vicariate Apostolic of Northern Kan-Su)
