London, or Greater London, is a region of England which forms the administrative boundaries of London. It is organized into 33 districts: the 32 London boroughs (which makes up the ceremonial county of Greater London) and the City of London (which is a separate county but still part of the region). The Greater London Authority, based in Southwark, is responsible for strategic local government across the region and consists of the Mayor of London and the London Assembly.The county of Greater London was created on 1 April 1965 through the London Government Act 1963. Administratively, Greater London was first established as a sui generis council area under the Greater London Council between 1963 and 1986. The area was re-established as a region in 1994, and the Greater London Authority formed in 2000.The region covers 1572km2 and had a population of 8,174,000 at the 2011 census. It has the highest GVA per capita in the United Kingdom at £37,232. The Greater London Built-up Area—used in some national statistics—is a measure of the continuous urban area of London, and therefore includes areas outside of the administrative region.