The United Kingdom of Great Britain and Northern Ireland is now commonly referred to as the UK. It is located in the northwest segment of Europe. It is both a parliamentary democracy and a constitutional monarchy that is made up of four constituent countries: England, Scotland, Wales and Northern Ireland. It is one of the few countries in the world that does not have a codified constitution, the other two being New Zealand and Israel. Its Parliament is made up of the Queen and two legislative houses�an elected House of Commons and an appointed House of Lords. Members do not have a limited term of office, but a new election must be called for within five years of the last election. The UK is a permanent member of the United Nations Security Council, a member of G8 and NATO, and has a �special relationship� with the United States. It has been a member of the European Union since 1973. The UK still controls many overseas territories that are remnants of the former British Empire which, at its height, encompassed about 25% of the world�s surface