London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a 50-mile (80 km) estuary down to the North Sea, and has been a major settlement for two millennia As one of the world's major global cities, London exerts a strong influence on its arts, entertainment, fashion, commerce and finance, education, health care, media, science and technology, tourism, and transport and communications. Its GDP (€801.66 billion in 2017) makes it the largest urban economy in Europe, and it is one of the major financial centres in the world.