London - city, capital of the United Kingdom and the centre of the Commonwealth. It lies astride the River Thames in southeastern England, 50 miles (80 km) from the river's estuary on the North Sea. The city was once the industrial, commercial, and political hub of a wealthy and extensive empire; it continues to be the United Kingdom's main centre of population, commerce, and culture.
A brief treatment of London follows. For full treatment (including a map), see London.
The chalk basin within which London is built is filled with younger sediments including solid rock, sands, clays, terraced pebble gravels, and Thames alluvium. The climate within the basin is relatively mild, with January to July mean temperatures ranging from 37.4 to 72.5 F (3 to 22.5 C); rainfall amounts to 21 inches (533 mm) a year.
Founded by the Romans as Londinium in the 1st century AD, the town experienced tremendous growth in trade and population during the late 16th and early 17th centuries. Extensive building projects were initiated after the Great Fire of 1666, and London became the dominant centre not only of the nation but of its expanding empire. During the 19th century, the problems caused by rapid industrialization, such as pollution and disease, were slowly remedied through advances in public health and other services. Heavy damage from aerial bombings during World War II brought the greatest setback in the history of modern London. Reconstruction and new development restored much of the city's grandeur, and relocation of manufacturing and shipping outside the city shrank its population and hastened its transition to a centre of international trade and finance. Tourism and retail trade are other major sectors of the city's economy; and, because London is the nation's capital, government services are also an important sector.
The City of London, about 1 square mile (2.7 square km) in area, is the core of an area called Inner, or Central, London, which contains the City of London and 13 of the 33 boroughs of Greater London. The central point in the City of London is an open space from which eight streets radiate. On the southern side is Mansion House, residence of the lord mayor of London. Lombard Street, the traditional banking street, is nearby, as are the Bank of England headquarters, the Royal Exchange, and the Stock Exchange. To the east is the fortress-castle known as the Tower of London, whose core dates from the late 11th century and is surrounded by constructions from many periods of English architecture. To the west lie the Inns of Court, longtime chambers and offices of barristers and lawyers-in-training, and the Royal Courts of Justice, or Law Courts. The City of London and the City of Westminster are linked by the Strand, an avenue upon which are located two of London's oldest churches, St. Clement Dane's and St. Mary-le-Strand.