At that time France was in the middle of the Nine Years' War (1688–97) of which the Williamite War in Ireland had been a theatre. Dillon and his regiment were sent to Roussillon and Catalonia, another theatre of this same war, where they fought the Spanish, among others at the siege of Roses under the Duc de Noailles, in 1693. In 1695 the duc de Vendôme succeeded to Noailles. Vendôme besieged Barcelona, which was defended by its governor, the conde de la Corzana, and by Prince George of Hesse-Darmstadt. The town surrendered on terms after a siege of 52 days on 10 August 1697.