London produces 19.5% of the UK's GDP, and is one of the world's major business, political and cultural centres. London is a leader in international finance, politics, communications, entertainment, fashion and the arts and has considerable influence worldwide. London is widely considered to be one of the world's major global cities.

London has an estimated population as of 1 January 2005 of 7.5 million and a metropolitan area population of between 12 and 14 million. London's population includes an extremely diverse range of peoples, cultures, and religions, making it one of the most cosmopolitan, vibrant and energetic cities on earth. Over 300 languages are spoken in London, making it one of the most linguistically diverse cities in the world.

London is the home of many global organisations, institutions and companies, and as such retains its leading role in world affairs. A city where cutting-edge meets tradition, London is a major tourist destination and an international transport hub. It has many important buildings and iconic landmarks, including world-famous museums, theatres, concert halls, galleries, airports, stadiums and palaces.

Unlike most capital cities, London's status as the Capital of the UK has never been granted or confirmed officially — by statute or in written form. Its position as the Capital has formed through constitutional convention, making its position as de facto Capital a part of the UK's unwritten constitution.