Uxbridge is a town in west London, England, and the administrative headquarters of the London Borough of Hillingdon. Fifteen miles (24.1 km) west-northwest of Charing Cross, it is one of the major metropolitan centres identified in the London Plan. Uxbridge historically formed part of the parish of Hillingdon in the county of Middlesex, and was a significant local commercial centre from an early time. As part of the suburban growth of London in the 20th century it expanded and increased in population, becoming a municipal borough in 1955, and has formed part of Greater London since 1965. It is a significant retail and commercial centre, and is the location of Brunel University and the Uxbridge campus of Buckinghamshire New University. The town is close to the boundary with Buckinghamshire, which is locally the River Colne.