The regiment was formed by Lieutenant General Robert Napier as the 53rd (Napier's) Regiment of Foot in 1755 for service in the Seven Years' War. The regiment started out in Exeter but was transferred to Leeds later in the same year. In the space of one month, 800 men had volunteered to serve for three years or as long as the country needed them to. It was re-ranked as the 51st (Brudenell's) Regiment of Foot, following the disbandment of the existing 50th and 51st regiments, in 1757. The regiment's first action was when it embarked on ships and took part in the Raid on Rochefort in September 1757 during the Seven Years' War.