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 1,572 km2 (607 sq mi) and had a population of 8,174,000 at the 2011 census. The Greater London county covers the same territory as the London region, save for the City of London which is a separate county. In 2012, it had 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 the administrative region.
The term Greater London has been and still is used to describe different areas in governance, statistics, history and common parlance.
In terms of ceremonial counties, London is divided into the small City of London and the much wider Greater London. This arrangement has come about because as the area of London grew and absorbed neighbouring settlements, a series of administrative reforms did not amalgamate the City of London with the surrounding metropolitan area, and its unique political structure was retained. Outside the limited boundaries of the City, a variety of arrangements has governed the wider area since 1855, culminating in the creation of the Greater London administrative area in 1965.
The term Greater London was used well before 1965, particularly to refer to the Metropolitan Police District (such as in the 1901 census), the area of the Metropolitan Water Board (favoured by the London County Council for statistics), the London Passenger Transport Area and the area defined by the Registrar General as the Greater London Conurbation. The Greater London Arterial Road Programme was devised between 1913 and 1916. One of the larger early forms was the Greater London Planning Region, devised in 1927, which occupied 1,856 square miles (4,810 km2) and included 9 million people.