For the region and county of England, see Greater London.For the historic city and financial district within London, see City of London. Clockwise from top: City of London skyline in the foreground with Canary Wharf skyline in the far background, Trafalgar Square, London Eye, Tower Bridge and a London Underground roundel in front of Elizabeth Tower 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, Greenwich defines the Prime Meridian, 0° longitude, and GMT).By the 11th century, London was beyond all comparison the largest town in England.

This was adapted into Latin as Londinium and borrowed into West Germanic, the ancestor-language of English, already before English had become widely spoken in Britain.

However, the etymology and original meaning of the British Celtic form is much debated.

Winchester had previously been the capital of Anglo-Saxon England, but from this time on, London became the main forum for foreign traders and the base for defence in time of war.

In the view of Frank Stenton: "It had the resources, and it was rapidly developing the dignity and the political self-consciousness appropriate to a national capital." In the 12th century, the institutions of central government, which had hitherto accompanied the royal English court as it moved around the country, grew in size and sophistication and became increasingly fixed in one place.

In 1100, its population was around 18,000; by 1300 it had grown to nearly 100,000.

During the Tudor period the Reformation produced a gradual shift to Protestantism, and much of London property passed from church to private ownership, which accelerated trade and business in the city.

Other landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar Square and The Shard.

London is home to numerous museums, galleries, libraries, sporting events and other cultural institutions, including the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library and West End theatres.

For most purposes this was Westminster, although the royal treasury, having been moved from Winchester, came to rest in the Tower.

While the City of Westminster developed into a true capital in governmental terms, its distinct neighbour, the City of London, remained England's largest city and principal commercial centre, and it flourished under its own unique administration, the Corporation of London.

By about 680, it had revived sufficiently to become a major port, although there is little evidence of large-scale production of goods.