London is the capital and most populous city of England and the United Kingdom. Standing on the River Thames, London has been a major settlement for two millennia, its history going back to its founding by the Romans, who named it Londinium.London's ancient core, the City of London, largely retains its 1.12-square-mile mediaeval boundaries and in 2011 had a resident population of 7,375, making it the smallest city in England. Since at least the 19th century, the term London has also referred to the metropolis developed around this core.[6] The bulk of this conurbation forms the Greater London administrative area (coterminous with the London region),governed by the Mayor of London and the London Assembly.