The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a sovereign state located off the north-western coast of continental Europe. The country includes the island of Great Britain (a term sometimes loosely applied to the whole state), the north-eastern part of the island of Ireland, and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another state: the Republic of Ireland. The UK’s form of government is a constitutional monarchy with a parliamentary system and its capital city is London. The current British monarch—since 6 February 1952—is Queen Elizabeth II.

The United Kingdom consists of four countries: England, Scotland, Wales and Northern Ireland. The United Kingdom is a developed country and has the world’s sixth-largest economy by nominal GDP and eighth-largest by purchasing power parity. The UK has a partially regulated market economy.