The Great Fire of London was a major conflagration that swept through the central parts of the English city of London, from Sunday, 2 September to Wednesday, 5 September 1666. The fire gutted the medieval City of London inside the old Roman City Wall. It threatened, but did not reach, the aristocratic district of Westminster, Charles II's Palace of Whitehall, and most of the suburban slums. It consumed 13,200 houses, 87 parish churches, St. Paul's Cathedral and most of the buildings of the City authorities. It is estimated to have destroyed the homes of 70,000 of the City's 80,000 inhabitants. The death toll is unknown but traditionally thought to have been small, as only six verified deaths were recorded. This reasoning has recently been challenged on the grounds that the deaths of poor and middle-class people were not recorded, while the heat of the fire may have cremated many victims leaving no recognisable remains.

London ⁱ/ˈlʌndən/ is the capital city of England and the United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located 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 square-mile mediaeval boundaries. Since at least the 19th century, the name London has also referred to the metropolis developed around this core. The bulk of this conurbation forms the London region and the Greater London administrative area, governed by the elected Mayor of London and the London Assembly.

London is a leading global city, with strengths in the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism and transport all contributing to its prominence. It is the world's leading financial centre alongside New York City and has the fifth-largest city GDP in the world (and the largest in Europe). London has been described as a world cultural capital. It was the world's most visited city during 2011 and London Heathrow is the world's busiest airport by number of international passengers. London's 43 universities form the largest concentration of higher education in Europe. In 2012 London will become the first city to host the modern Summer Olympic Games three times.