The UK comprises four nations: England, Scotland, Wales and Northern Ireland. Northern Ireland is the only one of these nations that is not part of Great Britain.
The United Kingdom has enjoyed a turbulent history, being the product of English expansionism, coupled with the effects of religious warfare in Ireland and Scotland, and a combination of poor governance and bad luck in Scotland regarding the economically crippling failure of the Darien scheme.
The UK presents a united team during the Olympic games, but each constituent nation has its own representation and most other major sporting events, including FIFA and UEFA football events, the Commonwealth games, and the IRB rugby competitions.
The UK is centrally ruled from London, and governed by Parliament in Westminster. However, Scotland, Wales and Northern Ireland each has their own national assembly with varying legislative powers.
The UK was the World's foremost power during the 18th and 19th centuries, but the effects of two World Wars robbed the UK (as it did for much of Europe) of a considerable amount of both mineral and human resources for much of the 20th century.
The UK is a member of the Security Council of the United Nations, the G8, NATO and the European Union.