Bristol is a city, unitary authority and county in South West England with an estimated population of 437,500 in 2014. It is England's sixth and the United Kingdom's eighth most populous city, and the most populous city in Southern England outside London. Bristol received a Royal charter in 1155. It was part of Gloucestershire until 1373 when it became a county in its own right. From the 13th to the 18th century, it ranked among the top three English cities after London, along with York and Norwich, on the basis of tax receipts, until the rapid rise of Manchester, Liverpool and Birmingham in the Industrial Revolution. It borders the counties of Somerset and Gloucestershire, with the historic cities of Bath and Gloucester to the south east and the north respectively. The city is built around the River Avon and also has a short coastline on the Severn Estuary which flows into the Bristol Channel. Bristol's prosperity has been linked with the sea since its earliest days. The Port of Bristol was originally in the city centre before being moved to the Severn Estuary at Avonmouth; Royal Portbury Dock is on the western edge of the city. In recent years, the economy has depended on the creative media, electronics and aerospace industries and the city centre docks have been regenerated as a centre of heritage and culture. People from Bristol are termed Bristolians.