London ( //) is the capital of England and the United Kingdom, the largestmetropolitan area in the United Kingdom and the largest urban zone in the European Union by most measures.[note 1] London has been a major settlement for two millennia,its history going back to its founding by the Romans, who called it Londinium.London's ancient core, the City of London, largely retains its square-mile mediaevalboundaries. 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 Londonregion and the Greater London administrative area,[note 2] governed by the electedMayor 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 largest financial centre alongside New York, has the largest city GDP in Europe and is home to the headquarters of more than 100 of Europe's 500 largest companies. It has the most international visitors of any city in the world. London Heathrow is the world's busiest airport by number of international passengers.London's 43 universities form the largest concentration of higher education institutions inEurope. In 2012 London will become the first city to host the Summer Olympicsthree times.
London has a diverse range of peoples, cultures and religions, and more than 300 languages are spoken within its boundaries. In July 2007 it had an official population of 7,556,900 within the boundaries of Greater London, making it the most populous municipality in the European Union. The Greater London Urban Area is the second largest in the EU with a population of 8,278,251, while London's metropolitan area is the largest in the EU with an estimated total population of between 12 million and 14 million.
London contains four World Heritage Sites: the Tower of London; Kew Gardens; the site comprising the Palace of Westminster, Westminster Abbey and St. Margaret's Church; and the historic settlement of Greenwich (in which the Royal Observatory marks theGreenwich Meridian (0° longitude) and GMT). Other famous landmarks includeBuckingham Palace, the London Eye, Piccadilly Circus, 30 St Mary Axe ("The Gherkin"), St Paul's Cathedral, Tower Bridge and Trafalgar Square. London is home to numerous museums, galleries, libraries, sporting events and other cultural institutions including the British Museum, National Gallery, British Library, Wimbledon and 40 theatres. London's Chinatown is the largest in Europe. The London Undergroundnetwork is the oldest underground railway network in the world and the most extensive after the Shanghai Metro.