United Kingdom is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning Great Britain, the northeast part of Ireland, and many small islands. Northern Ireland is the only part of the UK with a land border, sharing it with the Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, the North Sea, the English Channel and the Irish Sea. The largest island, Great Britain, is linked to France by the Channel Tunnel.

The UK is a developed country, with the fifth (nominal GDP) or sixth (PPP) largest economy in the world. It was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries, but the economic cost of two world wars and the decline of its empire in the latter half of the 20th century diminished its leading role in global affairs.

The UK nevertheless remains a major power with strong economic, cultural, military and political influence worldwide. It is a nuclear power and has the second or third highest defence spending in the world. It is a Member State of the European Union, holds a permanent seat on the United Nations Security Council, and is a member of the G8, NATO, OECD, World Trade Organization and the Commonwealth of Nations.