[Picture: Flag of the United Kingdom] The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK, or Britain,is a sovereign island countrylocated off the northwestern coast of mainland Europe. The UK includes the island of Great Britain, the northeast part of the island 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 United Kingdom is a unionof four constituent countries: England, Northern Ireland, Scotland and Wales. The United Kingdom is a par...more >>liamentary democracy with its seat of government in London, the capital. It is a constitutional monarchy with Her Majesty Queen Elizabeth II as the head of state. The Crown Dependencies of the Channel Islands and the Isle of Man, formally possessions of the Crown, are not part of the UK but form a federacy with it.The UK has fourteen overseas territories, all remnants of the British Empire, which at its height encompassed almost a quarter of the world's land surface, making it the largest empire in history. As a direct result of the empire, British influence can be observed in the language and culture of states such as Canada, Australia, New Zealand, India, Pakistan, South Africa, and the United States of America, and other less globally influential independent states. HM Queen Elizabeth II remains the head of the Commonwealth of Nations and head of state of the Commonwealth realms. The UK is a developed country, with the fifth (nominal GDP) or sixth (PPP) largest economy in the world.