In August 1808, during the Peninsular War, the 43rd fought in the Battle of Vimeiro which drove Napoleon's forces from Portugal. The campaign against the French then moved to Spain where in January 1809 the regiment took part in the retreat to Vigo and Corunna; achieving fame as part of the rearguard to the army before returning to England. In May 1809 the 1st battalion of the 43rd, as part of Sir Robert Craufurd's Light Brigade, sailed for Portugal to join Sir Arthur Wellesley's army. On landing at Lisbon the 43rd moved to Spain to support Wellesley's forces there. The battalion's march of 250 miles from Lisbon to Talavera included a march of fifty-two miles in twenty-six hours in the hottest season of the year. The battle of Talavera had been won before the battalion arrived. However, a company of the 43rd which had been at Lisbon from December 1808 fought in the battle as part of General Richard Stewart's brigade. In 1810 the 43rd formed part of the Light Division under the command of Sir Robert Craufurd. The 43rd fought in the battle of the crossing of the Côa in July 1810, the Battle of Bussaco in September 1810 and the Battle of Sabugal in April 1811. The 43rd also took part in the Battle of Fuentes de Oñoro in May 1811, the assault on the fortress of Ciudad Rodrigo in January 1812 and the Siege of Badajoz in April 1812; when storming the breach the 43rd lost 20 officers and 335 men.