Croydon is a major commercial centre in Greater London and the principal settlement of the London Borough of Croydon. It is 9.5 miles (15.3 km) south of Charing Cross, and is one of the major metropolitan centres identified in the London Plan.It is located on the natural transport corridor between London and England's south coast, just to the north of a gap in the North Downs. Historically a part of Surrey, at the time of the Norman conquest of England Croydon had a church, a mill and around 365 inhabitants (as recorded in the Domesday Book of 1086). Croydon expanded during the Middle Ages as a market town and a centre for charcoal production, leather tanning and brewing. The Surrey Iron Railway from Croydon to Wandsworth opened in 1803 and was the world's first horse-drawn railway, which later developed into an important means of transport facilitating Croydon's growth as a commuter town for the City of London and beyond.