Here we see the very dour Maj. General Hugo MacNeill of the Irish Army about 1923. Note the red staff pips on his collar and the Irish national harp insignia on his jacket buttons.
MacNeill was reportedly a bit of a scrapper and was the Irish Army’s cloak and dagger man.
As a teen he was a member of the Fianna Éireann, a sort of pre-IRA boy scouts before the IRA existed. This of course led to his service in the the Irish Volunteers (Óglaigh na hÉireann) which naturally morphed into the IRA proper after 1919. However, upon independence from the UK in 1922, he cast his lot with Michael Collins and the pro-Treaty National Army of the Irish Free State, becoming a Colonel in the regulars tasked with intelligence missions. He was then assistant Chief of Staff (as a Maj. Gen) after the Civil War, when this image was likely taken.
He remained at that grade through WWII, during which he commanded a division of the Irish Army during the island’s tense neutrality against all comers, founding an indigenous commando school and apparently was very chummy with both the Germans and the Brits during the conflict, as befitting a neutral.
He retired in the 1950s as a Lt. General and helped form the Irish equivalent of the American Legion for former servicemen.