In 1913, Ireland, the whole of Ireland, was an integrated and peaceful part of the UK – albeit one with a strong home rule movement and a strong counter-home rule movement. It had two private and opposing armies and a secret underground brotherhood dedicated to winning an Irish Republic by force. A world war, a rising, a guerilla war and a civil war later, most of Ireland had left the UK by 1923, becoming the Irish Free State, and of course, Northern Ireland was born. Ciarán Dunbar is joined by Professor Mike Cronin of Boston College Ireland.