The regiment sailed for Jersey in April 1809 and was then embarked for Portugal in August 1809 for service in the Peninsular War. It landed in Lisbon in February 1810 and arrived to take part in the defence of Fort Matagorda a few days later. Captain Archibald Maclaine led a detachment of 155 men who held back Marshal Soult with a force of 8.000 men. Maclaine was knighted for this exploit and promoted to Major. The regiment then saw action at the Battle of Sabugal in April 1811, the Battle of Fuentes de Oñoro in May 1811 and the siege of Ciudad Rodrigo in January 1812. After that it fought at the siege of Badajoz in March 1812, the Battle of Salamanca in July 1812 and the siege of Burgos in September 1812 as well as the Battle of Vitoria in June 1813. It then pursued the French Army into France and fought at the Battle of Nivelle in November 1813, the Battle of the Nive in December 1813 and the Battle of Orthez in February 1814 as well as the Battle of Toulouse in April 1814. It embarked for Cork in May 1814 and was disbanded in Dublin in December 1818.