Lisle spent the next three years with the Royalist field army based in Oxford, initially as Lieutenant-Colonel of dragoons under Arthur Aston. He took part in the October 1642 Battle of Edgehill and gained a reputation for courage and reliability, reportedly refusing to wear armour on occasion to reassure his men. In 1643, he fought at Chalgrove in May, was wounded at First Newbury in September and promoted colonel shortly after. He led an infantry regiment at Cheriton in March 1644 and during the campaign in the west commanded a brigade or tercio at Cropredy Bridge, Lostwithiel and Second Newbury.