London is the capital and largest city of England and the United Kingdom, with a population of 9.14 million people in 2025. Its wider metropolitan area is the largest in Western Europe, with a population of 15.4 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) tidal estuary down to the North Sea, and has been a major settlement for nearly 2,000 years. Its ancient core and financial centre, the City of London, was founded by the Romans as Londinium and has retained its medieval boundaries. The City of Westminster, to the west of the City of London, has been the site of the national government and parliament for centuries. London grew rapidly in the 19th century, becoming the world's largest city at the time. Since the 19th century the name "London" has referred to the metropolis around the City of London, historically split among the counties of Middlesex, Essex, Surrey, Kent and Hertfordshire. Since 1965 it has largely comprised the administrative area of Greater London, governed by 33 local authorities and the Greater London Authority.
As one of the world's major global cities, and ranked as Alpha++, London exerts a strong influence on world art, architecture, culture, cinema, entertainment, commerce, finance, education, healthcare, media, science, technology, tourism, transport and communications. London is Europe's largest city economy and one of the world's major financial centres. London is home to several of the world's leading academic institutions, such as the London School of Economics and Imperial College London, and hosts Europe's largest concentration of higher education institutions, comprising over 50 universities and colleges collectively enrolling more than 500,000 students in 2023. It is the most-visited city in Europe and has the world's busiest city airport system. The London Underground is the world's oldest rapid transit system.
London's diverse cultures encompass over 300 languages. The 2025 population of Greater London of just over 9.8 million made it Europe's third-most populous city, accounting for 13.1 per cent of the United Kingdom's population and 15.5 per cent of England's population. The Greater London Built-up Area is the fourth-most populous in Europe, with about 9.8 million inhabitants as of 2011. The London metropolitan area is the third-most-populous in Europe, with about 15 million inhabitants (referred to as Londoners) as of 2025, making London a megacity.
Landmarks include the Tower of London, Westminster Abbey, Buckingham Palace, the London Eye, Piccadilly Circus, St Paul's Cathedral, Tower Bridge, Trafalgar Square, the Palace of Westminster; and the historic village of Greenwich where the Royal Observatory defines the Prime Meridian (0° longitude) and Greenwich Mean Time. The city has the most museums, art galleries, libraries and cultural venues in the UK, including the British Museum, the National Gallery, the Natural History Museum, Tate Modern, the British Library and numerous West End theatres. Annual sporting events include the FA Cup Final (held at Wembley Stadium), the Wimbledon Tennis Championships and the London Marathon. It became the first city to host three Summer Olympic Games upon hosting the 2012 Summer Olympics after previously hosting in 1908 and 1948.
Etymology
The name London is attested in the first century AD, usually in the Latinised form Londinium. Modern scientific analyses of the name must account for the origins of the different forms that are found in early sources, such as Latin Londinium, Old English Lunden, and Welsh Llundein, with reference to the known developments over time of sounds in those different languages. The name came into these languages from Common Brythonic; the lost Celtic form of the name was most likely *Londonjon.
Until 1889, the name "London" applied officially only to the City of London, but since then it has also denoted the County of London and Greater London.
History
Prehistory
In 1993, remains of a Bronze Age bridge were found on the south River Thames foreshore, upstream from Vauxhall Bridge. Two of the timbers were radiocarbon dated to 1750–1285 BC. In 2010 foundations of a large timber structure, dated to 4800–4500 BC, were found on the Thames' south foreshore downstream from Vauxhall Bridge. Both are located on the south bank of the Thames, where the now-underground River Effra flows into the Thames.
Roman London
Despite the evidence of scattered Brythonic settlements in the area, the first major settlement was founded by the Romans around AD 47, about 4 years after their invasion of AD 43. This only lasted until about AD 61, when the Iceni tribe led by Queen Boudica stormed it and burnt it to the ground.
The next planned incarnation of Londinium prospered, superseding Colchester as the principal city of the Roman province of Britannia in 100. At its height in the 2nd century, Roman London had a population of about 60,000.
Anglo-Saxon and Viking-period London
With the early-5th-century collapse of Roman rule, the walled city of Londinium was effectively abandoned, although Roman civilisation continued around St Martin-in-the-Fields until about 450. From about 500 an Anglo-Saxon settlement known as Lundenwic developed slightly west of the old Roman city. By about 680 the city had become a major port again, but there is little evidence of large-scale production. From the 820s repeated Viking assaults brought decline.
The Vikings applied Danelaw over much of eastern and northern England from 886; The Anglo-Saxon Chronicle records that Alfred "refounded" London that year. This involved the abandonment of Lundenwic and a revival of life and trade within the old Roman walls. London then grew slowly until a dramatic increase in about 950.
By the 11th century, London was the largest town in England. Westminster Abbey, rebuilt in Romanesque style by King Edward the Confessor, was one of the grandest churches in Europe. Winchester had been the capital of Anglo-Saxon England, but from this time, 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."
Middle Ages
After winning the Battle of Hastings, William, Duke of Normandy, was crowned King of England as William I in the newly completed Westminster Abbey on Christmas Day 1066. He built the Tower of London to intimidate the inhabitants. In 1097 William II began building Westminster Hall, near the abbey. It became the basis of a new Palace of Westminster.
In the 12th century the institutions of central government, which had followed the royal English court around the country, grew in size and sophistication and became increasingly fixed, for most purposes at Westminster, although the royal treasury came to rest in the Tower of London. While the City of Westminster developed into a true governmental capital, its distinct neighbour, the City of London, remained England's largest city and principal commercial centre and flourished under its own unique administration, the Corporation of London. In 1100, its population was some 18,000; by 1300, it had grown to nearly 100,000. With the Black Death in the mid-14th century, London lost nearly a third of its population. London was the focus of the Peasants' Revolt in 1381.
London was a centre of England's Jewish population before their expulsion by Edward I in 1290. Violence against Jews occurred in 1190, when it was rumoured that Richard I had ordered their massacre after some of their leaders had presented themselves at his coronation. In 1264, during the Second Barons' War, Simon de Montfort's rebels killed 500 Jews while attempting to seize records of debts.
Early modern
The Reformation produced a shift to Protestantism. Much property passed into private ownership, accelerating business in the city. In 1475 the Hanseatic League set up a trading base. Woollen cloth was shipped undyed from 14th- and 15th-century London to the Low Countries. The reopening of the Netherlands to English shipping in January 1565 spurred a burst of commercial activity. Mercantilism grew and monopoly traders such as the East India Company were founded as trade expanded to the New World. London became the main North Sea port, with migrants from England and abroad. The population rose from about 50,000 in 1530 to about 225,000 in 1605. Shakespeare built his Globe Theatre in Southwark in 1599. Stage performances halted when Puritan authorities shut down the theatres in the 1640s. The ban was lifted during the 1660 Restoration; London's oldest theatre, Drury Lane, opened in 1663. By the end of the Tudor period in 1603, London was still compact. There was an assassination attempt on James I in Westminster, in the Gunpowder Plot of 5 November 1605. In 1637 the government of Charles I attempted to reform London's administration; the Corporation made "The Great Refusal", explaining the City of London's unique governmental status.
In the English Civil War, most Londoners supported the Roundheads. After an advance by the Cavaliers in 1642, culminating in the battles of Brentford and Turnham Green, London was surrounded by a defensive perimeter wall. The fortifications failed their only test when the New Model Army entered London in 1647. London suffered the Great Plague of 1665–1666, killing some 100,000 people, a fifth of the population. In 1666, the Great Fire destroyed much of the wooden-built city. Rebuilding took over 10 years, supervised by the polymath Robert Hooke.
In 1710, Christopher Wren's masterpiece St Paul's Cathedral was completed, replacing its medieval predecessor, lost in the Great Fire. Its dome dominated the London skyline for centuries, inspiring William Blake, whose 1789 poem "Holy Thursday" mentions 'the high dome of Pauls'. During the Georgian era new districts such as Mayfair were formed in the west, while new bridges encouraged development in South London. In the east, the Port of London expanded downstream, while the financial centre matured. In 1762 George III acquired Buckingham House. During the 18th century London was dogged by crime, and the Bow Street Runners were established in 1750 as a professional police force. Epidemics during the 1720s and 30s saw most children born in the city die before reaching their fifth birthday. Growing literacy and printed papers made news widely available; Fleet Street became the centre of the British press, and Londoners debated in coffeehouses. Napoleon's invasion of Amsterdam led many financiers to relocate to London and the first London international issue was arranged in 1817. The Royal Navy became the world's leading war fleet, acting as a deterrent to economic adversaries. Following an 1838 fire, the Royal Exchange was rebuilt in 1844. The 1846 repeal of the Corn Laws, meant to weaken Dutch economic power, enabled London to overtake Amsterdam as the leading international financial centre.
Late modern and contemporary
The Industrial Revolution saw unprecedented urbanisation. London was the world's largest city from about 1831 to 1925, with a population density of 132 per acre (325 per hectare). Harding, Howell & Co. on Pall Mall was one of the first department stores, alongside many street sellers. The London Underground, the world's first urban rail network, was created in response to traffic congestion. Overcrowding led to cholera epidemics, claiming 14,000 lives in 1848, and 6,000 in 1866. A modern sewage system was created by the Metropolitan Board of Works; it diverted waste to the Thames Estuary, and by the 1890s used biological treatment of sewage to oxidise the waste. The Metropolitan Board of Works oversaw infrastructure expansion in the capital and some surrounding counties. In 1894, Lyons opened their first chain of teashops in Piccadilly. Tearooms became popular meeting places for women from the suffrage movement. Westminster Abbey and St Paul's Cathedral were bombed in the 1912–14 suffragette bombing and arson campaign.
London was bombed by the Germans in the First World War. During the Second World War, the Blitz killed over 30,000 Londoners, destroying many buildings. The tomb of the Unknown Warrior was created in Westminster Abbey on 11 November 1920 and The Cenotaph, in Whitehall, was unveiled on the same day; it is the focus the National Service of Remembrance held annually on Remembrance Sunday. The 1948 Summer Olympics were held at the original Wembley Stadium, while London was still recovering from the war. From the 1940s, London became home to many immigrants, primarily from Commonwealth countries such as Jamaica, India, Bangladesh and Pakistan, making London one of the most multiracial cities in the world. In 1951 the Festival of Britain was held on the South Bank. The Great Smog of 1952 led to the Clean Air Act 1956, which ended the "pea soup fogs" which had earned London the nickname the "Big Smoke".
In the mid-1960s, London became a centre for worldwide youth culture, exemplified by the Swinging London sub-culture of the King's Road, Chelsea and Carnaby Street. The role of trendsetter revived in the punk era. In 1965 London's political boundaries were expanded in response to the city's growth, and a new Greater London Council was created. During the Troubles in Northern Ireland, London was hit by bomb attacks by the Provisional Irish Republican Army beginning in 1973. These attacks lasted for two decades, starting with the Old Bailey bombing. Greater London's population declined after the Second World War, from an estimated peak of 8.6 million in 1939 to around 6.8 million in the 1980s. By January 2015 Greater London's population had increased again to 8.63 million. The principal ports for London moved downstream to Felixstowe and Tilbury, with the London Docklands area becoming a focus for regeneration. 2 miles (3.2 km) east of central London, the Thames Barrier was completed in 1982 to protect London against tidal surges from the North Sea.
The Greater London Council was abolished in 1986, leaving London with no central administration until the creation of the Greater London Authority in 2000. To mark the 21st century the Millennium Dome, the London Eye and the Millennium Bridge were constructed. On 7 July 2005, three London Underground trains and a double-decker bus were bombed in a series of terrorist attacks. In 2008 Time magazine hailed London as one of the world's three most influential global cities. In terms of international connectedness, as of 2024, London was one of two cities worldwide classified as an "Alpha++" city by the Globalization and World Cities Research Network.