The United Kingdom, officially the United Kingdom of Great Britain and Northern Ireland, is a sovereign and insular country, member of the European Union, located northwest of Continental Europe. Its territory is formed geographically by the island of Great Britain, the northeast of the island of Ireland and small adjacent islands. Northern Ireland is the only part of the country with a land border, which separates it from the Republic of Ireland. Great Britain bounded on the north and west by the Atlantic Ocean, on the east by the North Sea, on the south by the English Channel and on the west by the Irish Sea.
The United Kingdom is a unitary State comprised of four constituent nations: Scotland, Wales, England and Northern Ireland, governed by a parliamentary system with headquarters and capital in London, but with three decentralized national administrations in Edinburgh, Cardiff and Belfast, the capitals of Scotland, Wales and Northern Ireland, respectively. It is a parliamentary monarchy, with Isabel II the head of state. Colloquially and erroneously is denominated Great Britain and England, consequence of the greater weight of both within the State. The dependencies of the Crown of the Channel Islands - Jersey and Guernsey - and the Isle of Man are not part of the United Kingdom, although the British Government is responsible for their defense and international relations. The United Kingdom has fourteen overseas territories, all vestiges of what was the British Empire, which in its international territory came to reach and cover about a fifth of the world's land area.
Isabel II continues to be at the head of the Commonwealth of Nations and as head of State of each of the Kingdoms of the Commonwealth. It is a developed country that by its net volume of gross domestic product is the fifth world economy. It was the first industrialized country in the world and the main world power during the nineteenth century and the beginning of the twentieth century, but the economic cost of the two world wars and the decline of its empire in the second part of the 20th century diminished its role in international relations. However, it still maintains a significant economic, cultural, military and political influence, and is a nuclear power.
It is a member state of the European Union, one of the five permanent members of the Security Council of the United Nations with the right of veto, member of the G7, the G-20, NATO, the OECD, the UKUSA, the Commonwealth of Nations and the Common Travel Area.