London is the capital and largest city of the United Kingdom of great Britain and Northern Ireland. Administratively, it forms the Greater London region of England, divided into 33 self-governing territories. With a population of 8.6 million (2015), it is the third largest city in Europe. It forms the Metropolitan area of Greater London and the wider Metropolitan area. Located in the South-East of the island of great Britain, on a plain at the mouth of the Thames, near the North sea. The main political, economic and cultural centre of the United Kingdom.
London is one of the world's top global cities and leading financial centres. Its economy is one fifth of the country's economy.
Founded by the Romans shortly after their invasion of Britain in 43 ad About 100 ad — the capital of Roman Britain, from XI—XII centuries — England, from 1707 — Britain, from XVI to XX century — the British Empire. From 1825 to 1925, London was the largest city in the world.
The historic city centre, formed by the Westminster and city districts, dates back to the Victorian era. Among the few buildings that survived the fire of 1666 — the medieval citadel tower.