His father's cousin, yet another Richard Ingoldsby (1665-1712), served with Marlborough during the War of the Spanish Succession and appointed Commander-in-Chief, Ireland in 1707. In April 1707, the younger Ingoldsby was commissioned into his regiment, the 18th Foot, later Royal Irish, and served with it in Flanders. The 18th fought at Oudenarde and Malplaquet until the war ended in 1713, by which time Ingoldsby was a captain.