Ross was promoted brigadier-general on 9 March 1702, and major-general on 1 January 1704. He commanded a brigade of dragoons at the battles of Blenheim, Ramillies, Oudenarde and Malplaquet. He was further promoted to lieutenant-general on 1 January 1707, made Colonel-General of all the Dragoon Forces on 1 May 1711, and promoted to full general on 1 January 1712. He was removed from the colonelcy of the Royal Dragoons of Ireland by George I on 8 October 1715, but reappointed on 1 February 1729, holding the post until his death.