Family, I suppose

Apparently he was an extremely able officer. The condition of the Irish Armed Forces under De Valera was a disgrace, though. Not a single anti-tank gun in the whole country in 1939, and no actual navy either.

The high point of his time as GOC 1st Division was a massive exercise that took place around 1942 where he put his division through a tough exercise all over the southern Free State to show that they could react quickly at any point in the area. He'd worked things up by then that it would have taken at least three divisions of either the British or German army to even effect a landing, and they'd have had to contend with a variety of plans to fall back and wreak havoc on any invading forces. And this from a man that went from being, in effect, a high school dropout to head of Irish Army Intelligence and a graduate of the U.S. Army Staff College in the 1930s. He was apparently an auto-didact of truly awesome proportions.