Location of London in the United Kingdom
|Coordinates: 51°30′26″N 0°7′39″W / 51.50722°N 0.12750°W
||c.43 AD (as
| • Type
| • Body
Greater London Authority
| • Elected body
Sadiq Khan (
| • London Assembly
||1,572 km2 (607 sq mi)
||1,737.9 km2 (671.0 sq mi)
||8,382 km2 (3,236 sq mi)
||35 m (115 ft)
| • Density
||5,518/km2 (14,290/sq mi)
|GVA (nominal; 2015)
| • Total
||£510 billion/ $717 billion
| • Per capita
| • Summer (
- 020, 01322, 01689, 01708, 01737, 01895, 01923, 01959, 01992
City of London Police and
City (Both within Greater London)
Southend (Outside Greater London)
i is the
capital and most populous city of
England and the
 Standing on the
River Thames in the south east of the island of
Great Britain, London has been a major settlement for two millennia. It was founded by the
Romans, who named it
 London's ancient core, the
City of London, largely retains its 1.12-square-mile (2.9 km2)
medieval boundaries. Since at least the 19th century, "London" has also referred to the metropolis around this core, historically split between
 which today largely makes up
[note 1] governed by the
Mayor of London and the
London is a leading
 in the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism, and transport.
 It is one of the world's leading
 and has the
fifth- or sixth-largest metropolitan area GDP in the world.
 London is a world cultural capital.
 It is the world's most-visited city as measured by international arrivals
 and has the
world's largest city airport system measured by passenger traffic.
 London is the world's leading
 hosting more
ultra high-net-worth individuals
 than any other city. London's universities form the largest concentration of higher education institutes in Europe,
 and a 2014 report placed it first in the world university rankings. According to the report London also ranks first in the world in software, multimedia development and design, and shares first position in technology readiness.
2012, London became the only city to have hosted the modern
Summer Olympic Games three times.
London has a diverse range of people and cultures, and more than 300 languages are spoken in the region.
 Its estimated mid-2015 municipal population (corresponding to Greater London) was 8,673,713,
 the largest of any
city in the European Union,
 and accounting for 12.5 per cent of the UK population.
London's urban area is the second
most populous in the EU, after
Paris, with 9,787,426 inhabitants at the 2011 census.
city's metropolitan area is one of the
most populous in Europe with 13,879,757 inhabitants,
 while the
Greater London Authority states the population of the city-region (covering a large part of the south east) as 22.7 million.
 London was the
world's most populous city from
around 1831 to 1925.
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 marks the
Prime Meridian, 0°
 Other famous landmarks include
Buckingham Palace, the
St Paul's Cathedral,
Trafalgar Square, and
The Shard. London is home to numerous
museums, galleries, libraries,
sporting events and other cultural institutions, including the
Natural History Museum,
British Library and
West End theatres.
London Underground is the oldest underground railway network in the world.
etymology of London is uncertain.
 It is an ancient name, found in sources from the 2nd century. It is recorded c.121 as
Londinium, which points to
 and hand-written Roman tablets recovered in the city originating from AD 65/70-80 include the word Londinio ("in London").
 The earliest attempted explanation, now disregarded, is attributed to
Geoffrey of Monmouth in
Historia Regum Britanniae.
 This had it that the name originated from a supposed
King Lud, who had allegedly taken over the city and named it Kaerlud.
From 1898, it was commonly accepted that the name was of
Celtic origin and meant "place belonging to a man called *Londinos"; this explanation has since been rejected.
Richard Coates proposed in 1998 that it is derived from the pre-Celtic
Old European *(p)lowonida, meaning "river too wide to ford", and suggested that this was a name given to the part of the
River Thames which flows through London; from this, the settlement gained the Celtic form of its name, *Lowonidonjon;
 this requires quite a serious amendment however. The ultimate difficulty lies in reconciling the Latin form Londinium with the modern Welsh Llundain, which should demand a form *(h)lōndinion (as opposed to *londīnion), from earlier *loundiniom. The possibility cannot be ruled out that the Welsh name was borrowed back in from English at a later date, and thus cannot be used as a basis from which to reconstruct the original name.
Until 1889, the name "London" officially applied only to the
City of London, but since then it has also referred to the
County of London and now to