During the First World War, the Regiment raised 11 battalions. The 1st Battalion was part of the 86th Brigade of the 29th Division and participated in the landing at V Beach, Cape Helles, on 25 April 1915. It was among the first to disembark from the SS River Clyde and, together with the Royal Dublin Fusiliers, suffered horrific casualties under Turkish machine gun fire. Corporal William Cosgrove (1888-1936) was awarded the battalions’ first Victoria Cross for single-handedly pulling down Turkish wire entanglements which were preventing the advance of those who had made it to the shore. Until new drafts arrived, the survivors of the two fusilier battalions were temporarily combined to form a single unit known as the ‘Dubsters’.
The 2nd Battalion remained on the Western Front throughout the war and was never out of earshot of the front line. It is perhaps best remembered for its valour during the Battle of Neuve Chapelle in March 1915, when it was one of just two battalions to reach the German lines. The day before the attack, the 2nd Battalion’s 389 men had received an absolution from their chaplain, Father Francis Gleeson (1884-1959). By 11 o’clock the following morning, 151 of them were dead. The battalion subsequently saw action at Loos, Somme and Passchendaele.
The Regiment was disbanded in 1922 under the terms of the Anglo-Irish Treaty.