
The London metropolitan area is the third-most populous in Europe after Istanbul's and Moscow's, with 14,040,163 inhabitants in 2016. Greater London Built-up Area is the fourth most populous in Europe, after Istanbul, Moscow and Paris, with 9,787,426 inhabitants at the 2011 census. It accounts for 13.4 per cent of the UK population. The mid-2018 population of Greater London of about 9 million, made it Europe's third-most populous city. London's diverse cultures mean over 300 languages are spoken.

In 2012, London became the first city to host three Summer Olympic Games. The city is home to the most 5-star hotels of any city in the world. With Europe's largest concentration of higher education institutions, it includes Imperial College London in natural and applied sciences, the London School of Economics in social sciences, and the comprehensive University College London. In 2019 it had the second highest number of ultra high-net-worth individuals in Europe after Paris and the second-highest number of billionaires of any city in Europe after Moscow. Its GDP (€801.66 billion in 2017) makes it the biggest urban economy in Europe and one of the major financial centres in the world. London, as one of the world's global cities, exerts strong influence on its arts, commerce, education, entertainment, fashion, finance, health care, media, tourism and communications. The City of Westminster, to the west of the City, has for centuries held the national government and parliament. Since the 19th century, "London" has also referred to the metropolis around this core, historically split between the counties of Middlesex, Essex, Surrey, Kent, and Hertfordshire, which largely makes up Greater London, the region governed by the Greater London Authority. The City of London, its ancient core and financial centre, was founded by the Romans as Londinium and retains boundaries close to its medieval ones. Standing on the River Thames in south-east England at the head of a 50-mile (80 km) estuary down to the North Sea, it has been a major settlement for two millennia. London is the capital and largest city of England and the United Kingdom. Metropolitan (excluding the City of London square-mile)
