The regiment embarked for Portugal in July 1808 for service in the Peninsular War. The regiment fought in the Battle of Roliça and the Battle of Vimeiro in August 1808, the Battle of Corunna in January 1809 and the Battle of Bussaco in September 1810. It earned the nicknames the "Old and Bold", "The Fighting Fifth" and also "Lord Wellington's Bodyguard". It formed part of a small force which beat off an overwhelming body of the enemy at El Boden in 1811, a performance which Wellington notified to the Army as "a memorable example of what can be done by steadiness, discipline, and confidence".