London is the capital and largest city of England and the United Kingdom. Located in southeast England on the River Thames, it sits at the head of a 50-mile tidal estuary that leads to the North Sea. As of 2024, the city has a population of 9.1 million people, while its wider metropolitan area is the largest in Western Europe with a population of 15.4 million.
The settlement has existed for nearly 2,000 years. Its ancient core and financial center, the City of London, was originally founded by the Romans as Londinium and maintains its medieval boundaries. To the west lies the City of Westminster, which has served as the site of the national government and parliament for centuries.
London experienced rapid growth during the 19th century, becoming the world's largest city at that time. Since 1965, the metropolis has largely comprised the administrative area of Greater London, which is governed by 33 local authorities and the Greater London Authority.