 Ireland is the second-largest island of the British Isles, the third-largest in Europe, and the twentieth-largest on Earth.Geopolitically, Ireland is divided between the Republic of Ireland (officially named Ireland), which covers five-sixths of the island, and Northern Ireland, which is part of the United Kingdom.In 2011, the population of Ireland was about 6.6 million, ranking it the second-most populous island in Europe after Great Britain.