London is the capital and largest city of England and the United Kingdom.[8][9] 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.[10] 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.[note 1][11][12][13][14][15] Since the 19th century,[16][17][18] "London" has also referred to the metropolis around this core, historically split between the counties of Middlesex, Essex, Surrey, Kent, and Hertfordshire,[19] which largely makes up Greater London,[20] the region governed by the Greater London Authority.[note 2][21][22][23] The City of Westminster, to the west of the City, has for centuries held the national government and parliament.

Willis Building
Clockwise from top: City of London in the foreground with Canary Wharf in the far background, Trafalgar Square, London Eye, Tower Bridge and a London Underground roundel in front of Elizabeth Tower
Location within the United Kingdom
Location within England
Location within Europe
London (Earth)
Coordinates: 51°30′26″N 0°7′39″W
Sovereign state United Kingdom
Country England
CountiesGreater London
City of London
Settled by RomansAD 47[1]
as Londinium
DistrictsCity of London and 32 boroughs
  TypeExecutive mayoralty and deliberative assembly within unitary constitutional monarchy
  BodyGreater London Authority
Mayor Sadiq Khan (L)
London Assembly
  London Assembly14 constituencies
  UK Parliament73 constituencies
  Total[upper-alpha 1]1,572 km2 (607 sq mi)
1,737.9 km2 (671.0 sq mi)
8,382 km2 (3,236 sq mi)
  City of London2.90 km2 (1.12 sq mi)
  Greater London1,569 km2 (606 sq mi)
Elevation11 m (36 ft)
  Total[upper-alpha 1]8,961,989[4]
  Density5,666/km2 (14,670/sq mi)
14,257,962[5] (1st)
  City of London
8,706 (67th)
  Greater London
GVA (2019)
  Total£503 billion
($642 billion)
  Per capita£56,199
Time zoneUTC (Greenwich Mean Time)
  Summer (DST)UTC+1 (British Summer Time)
Postcode areas
22 areas
Area codes
  • 020, 01322, 01689, 01708, 01737, 01895, 01923, 01959, 01992
Budget£19.376 billion
($25 billion) [7]
International airportsHeathrow (LHR)
City (LCY)
Gatwick (LGW)
Stansted (STN)
Luton (LTN)
Southend (SEN)
Rapid transit systemUnderground
PoliceMetropolitan (excluding the City of London square-mile)

London, as one of the world's global cities,[24] exerts strong influence on its arts, commerce, education, entertainment, fashion, finance, health care, media, tourism and communications.[25] Its GDP (€801.66 billion in 2017) makes it the biggest urban economy in Europe[26] and one of the major financial centres in the world. In 2019 it had the second highest number of ultra high-net-worth individuals in Europe after Paris[27] and the second-highest number of billionaires of any city in Europe after Moscow.[28] With Europe's largest concentration of higher education institutions,[29] it includes Imperial College London in natural and applied sciences, the London School of Economics in social sciences, and the comprehensive University College London.[30] The city is home to the most 5-star hotels of any city in the world.[31] In 2012, London became the first city to host three Summer Olympic Games.[32]

London's diverse cultures mean over 300 languages are spoken.[33] The mid-2018 population of Greater London of about 9 million,[3] made it Europe's third-most populous city.[34] It accounts for 13.4 per cent of the UK population.[35] 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.[36][37] The London metropolitan area is the third-most populous in Europe after Istanbul's and Moscow's, with 14,040,163 inhabitants in 2016.[note 3][5][38]

London covers four World Heritage Sites: the Tower of London; Kew Gardens; the Palace of Westminster along with Westminster Abbey, and St Margaret's Church, and the historic settlement in Greenwich, where the Royal Observatory, Greenwich defines the Prime Meridian (0° longitude) and Greenwich Mean Time.[39] Other landmarks include Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge and Trafalgar Square. It has numerous museums, galleries, libraries and sporting venues, including the British Museum, National Gallery, Natural History Museum, Tate Modern, British Library and West End theatres.[40] The London Underground is the oldest rapid transit system in the world.