A new two-part BBC television series brings into sharper focus the story of Ireland's role in World War One.
More than 200,000 Irishmen from all parts of the island marched to war, unified in their commitment to fight but deeply divided in their reasons for doing so.
As the war was being fought on the fields of mainland Europe, Ireland was breaking apart.
While it was still a part of the British empire, the country was on the verge of a civil war between nationalists and unionists.
When Britain declared war on Germany, many nationalists and unionists found a unified cause and joined up to fight.
While soldiers were doing battle abroad, political turmoil at home continued to brew and the 1916 Easter Rising in Dublin was a pivotal point in history.
The story of Ireland and World War One has often been shrouded in myth, but since the peace process in the past 20 years or so, new voices have been shedding light on that history.
The programme brings together three Irish history experts to take a fresh look at the story of Ireland and the Great War: Diarmaid Ferriter of University College Dublin, Richard Grayson from University of London and Timothy Bowman from the University of Kent.
Ireland's Great War begins on BBC One Northern Ireland at 18:00 GMT on Sunday 1 February, and will be available on iPlayer afterwards.