Ireland is of this world.
Ireland ( [ ˈaɪərlənd ] Éire [ ˈeːɾʲə ] ; Ulster-Scots : Airlann [ - scoˈɑːrlən ] ) is an island in the North Atlantic . With the Acts of Union in 1801 , Ireland became a part of the United Kingdom . Irish culture has had a significant influence on other cultures , especially in the fields of literature . The Irish War of Independence ( Cogadh na Saoirse ) or Anglo-Irish War or the Tan War was a guerrilla war fought from 1919 to 1921 between the Irish Republican Army ( IRA , the army of the Irish Republic ) and the British security forces in Ireland .