The United Kingdom is a political union made up of four constituent countries: England, Scotland, and Wales on the island of Great Britain, and Northern Ireland. The United Kingdom also has several overseas territories, including Gibraltar and the Falkland Islands. The Crown has a relationship with the dependencies of the Isle of Man and the Channel Islands; they are part of the British Islands but not part of the United Kingdom. A constitutional monarchy, the United Kingdom has close relationships with fifteen other Commonwealth Realms that share the same monarch Queen Elizabeth II as head of state.
A member of the G8, the United Kingdom is a highly developed country with the fifth-largest gross domestic product in the world. It is the third most populous state in the European Union and is a founding member of the North Atlantic Treaty Organization (NATO) and the United Nations (UN) where it holds a permanent seat on the Security Council. The UK is also one of the world's major nuclear powers. Having previously been the hub of the world's most geographically extensive empire it retains an important and influential role in international politics, helped by the dominance of the English language in global affairs and its close ties with the United States of America.