Carlisle is a city and the largest settlement in Cumbria, North West England. It is part of the City of Carlisle local government district, and acts as the administrative centre for both this district and Cumbria County Council. The population of the urban area of Carlisle was 71,773 according to the 2001 census, with about 100,734 living in the wider district. Historically the county town of Cumberland, Carlisle developed importance as a military stronghold due to its position at the Anglo-Scottish border; Carlisle Castle, still relatively intact, was built in 1092 by William Rufus, and having once served as a prison for Mary, Queen of Scots.