The UK works with international institutions such as the United Nations, NATO, the Commonwealth and the European Union.
NATO was founded in 1949, and more than 60 years later, is still vital to the security of the UK.
The European Union comprises 27 member states. Britain has been a member since 1973.
Find out more about the work of the United Nations
Find out more about the European Union
Find out about the history of NATO, its objectives and the UK's role in the institution.
The Commonwealth turned 60 in 2009, learn more about its members and values