He entered the French army in 1721 .
He served in the war of 1734 against Austria ; he was present at Dettingen ( 1743 ) , and commanded the regiment de Lally in the famous Irish brigade at Fontenoy ( May 1745 ) .
Entering the French army in 1721 , he served in the war of 1734 against Austria ; he was present at Dettingen ( 1743 ) , and commanded the regiment de Lally in the famous Irish brigade at Fontenoy ( May 1745 ) .