Who ruled London?

London grew up at the lowest point where the Thames could be bridged, far enough inland to be sheltered but still reachable by sea-going ships on the tide. That combination of bridge and port explains almost everything about its history. A Roman foundation, it became the largest city in England by the early Middle Ages, the seat of the English crown at neighbouring Westminster, and eventually the capital of a world empire. Fire, plague and bombing have repeatedly destroyed it, but the old street plan and the twin centres of the City and Westminster have survived each rebuilding.

There is little sign of a major settlement before the Romans. After their invasion of 43 CE they bridged the Thames and, within a few years, founded Londinium on the north bank, which quickly became a busy trading town. Around 60 or 61 CE the rebel queen Boudica burned it to the ground, but it was rebuilt and by the second century was the largest town in Roman Britain, enclosed around 200 CE by a stone wall whose line still marks the boundary of the City. When Roman rule in Britain ended early in the fifth century, the walled town was largely abandoned.

The Anglo-Saxons built a new trading settlement, Lundenwic, a little to the west along today's Strand. Viking raids in the ninth century drove people back inside the old walls, and in 886 Alfred the Great took control of London and refortified it. Edward the Confessor built his abbey and palace at Westminster, upriver from the City, and after the Battle of Hastings William the Conqueror was crowned there on Christmas Day 1066 and began the Tower of London. Over the following centuries the City won wide rights of self-government under its mayor, while Westminster became the home of the royal court, the law courts and Parliament.

Medieval London suffered terribly from the Black Death of 1348 to 1349 and saw the Peasants' Revolt reach its streets in 1381. Under the Tudors it grew quickly through trade, and by 1600 it held perhaps 200,000 people. Many of the playhouses of William Shakespeare's era stood just outside the City's jurisdiction, on the south bank or in the northern suburbs.

The Great Plague of 1665 killed around a fifth of the population, and in September 1666 the Great Fire destroyed most of the medieval City, including the old St Paul's Cathedral. Rebuilding in brick and stone followed, with Christopher Wren's new St Paul's and dozens of parish churches. The founding of the Bank of England in 1694 and the growth of overseas trade made London a financial centre, and in the nineteenth century, as capital of the British Empire and the busiest port in the world, it became the largest city on earth, passing 6 million people by 1900.

Growth brought slums, cholera and the "Great Stink" of 1858, which prompted Joseph Bazalgette's sewer system. Railways and, from 1863, the world's first underground railway let the city spread outwards. During the Second World War the Blitz of 1940 to 1941 and later rocket attacks killed tens of thousands of Londoners and devastated the docks and the City. After the war the docks closed, immigration from the Commonwealth transformed the population, and finance replaced shipping as the city's engine. London hosted the Olympic Games for the third time in 2012. Greater London now has about 9 million people and is the capital of the United Kingdom and one of the world's leading financial centres.