When the War of the Spanish Succession began in 1701, he was reactivated and fought at the battles of Schellenberg, Blenheim and Ramillies. He was promoted captain in April 1707. In March 1708, he was commissioned as a lieutenant in the Foot Guards, although only 16 of its nominal 24 companies were actually formed, and Blakeney remained with his original unit. Under the practice known as double-ranking, Guards officers held a second, higher army rank; for example, a Guards lieutenant ranked as an army major. Guard units were rarely disbanded, and their officers were given precedence when deciding promotions, making it a cheap way to reward competent, but poor officers. John Huske (1692–1761), a colleague during the 1745 Rebellion, was commissioned in the Guards for similar reasons.