Northwest London; Kensington with Kensington Gardens and Hyde Park, top; Battersea Bridge and the Thames, bottom (by white area), Royal Hospital Chelsea; 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. London's ancient core, the City of London, largely retains its 1.12-square-mile (2.9 km2) medieval boundaries and in 2011 had a resident population of 7,375, making it the smallest city in England. The Greater London Authority estimated Greater London population to be 8.63 million in 2015, the largest of any municipality in the European Union, and accounting for 12.5 percent ...