London is the capital of the United Kingdom. It comprises 32 boroughs as well as the City of London which is where the Roman military camp Londinium was set up approximately 43AD. There are around 7.4 million people in Greater London (the City and 32 London Boroughs).
The City of London is in fact one of the smallest cities in the UK at only about a square mile. The term London, as commonly used, refers in fact to Greater London, which covers an area of approximately 1584km2 and includes the actual city, the surrounding business district and the surrounding residental neighbourhoods.