Bromley is a large suburban town in south east London, England and the administrative headquarters of the London Borough of Bromley. It is located 9.3 miles (15 km) south east of Charing Cross and is one of the major metropolitan centres identified in the London Plan. It was historically a market town, and prior to 1965 was in the county of Kent and formed the administrative centre of the Borough of Bromley. Its location on a coaching route and the opening of a railway station in 1858 were key to its development and the economic history of Bromley is underpinned by a shift from an agrarian village to commercial and retail hub. As part of the suburban growth of London in the 20th century, Bromley significantly increased in population and has formed part of Greater London since 1965. It has developed into one of a handful of regionally significant commercial and retail districts outside central London.