During the Irish Civil War, he held one of the highest ranks, as major general, in the pro-Treaty National Army but resigned his command following the death of Collins.

[1] He joined the nationalist militia, the Irish Volunteers in 1913 and the following year, though only fifteen, was involved in the smuggling of arms into Ireland.

Emmet Dalton initially joined the 7th Battalion of the Royal Dublin Fusiliers (RDF) as a temporary 2nd Lieutenant.

[4] Among the casualties was Tom Kettle, a former nationalist Member of Parliament and personal friend of Dalton's father and of Emmet.

[6][7] Afterwards he was transferred to the 6th Battalion, Leinster Regiment, and sent to Salonika then Palestine, where he commanded a company and then supervised a sniper school in El Arish.

[8] As assistant director of training,[9] he became close to Michael Collins and was involved in the Squad, the Dublin-based assassination unit.

The Treaty was opposed by much of the IRA and the Irish Civil War between pro and anti-treaty factions eventually resulted.

Dalton was in command of troops assaulting the Four Courts in the Battle of Dublin which marked the start of the war in June 1922.

[2] In spite of firm loyalty to the National Army, he was critical of the Free State's failure to follow up its victory, allowing the anti-treaty IRA to regroup resuming the guerrilla warfare started in 1919.

[12] Emmet Dalton died in his daughter Nuala's house in Dublin in 1978 on his 80th birthday, never having seen the film that Cathal O'Shannon of RTÉ had made on his life.