Ireland is the third largest island in Europe behind Great Britain and Iceland. It is also the twentieth largest in the world. It lies to the northwest of Continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain. Politically, the Republic of Ireland covers five sixths of the island, with Northern Ireland, part of the United Kingdom, covering the remainder in the northeast.

Ireland gained its independence from hundreds years of British ruling in 1921. The state was neutral during World War II, which was known internally as The Emergency. It offered some assistance to the Allies, especially in Northern Ireland. It is estimated that around 50,000 volunteers from Éire/Ireland joined the British armed forces during the second World War. In 1949, Ireland declared itself to be a republic and that henceforth it should be described additionally as the Republic of Ireland.