The 1st/36th were stationed at Battle, Sussex where they were brought up to strength before sailing from Portsmouth, arriving in Lisbon on 5 March 1811. They formed part of an army of reinforcements as the British began a new offensive aimed at breaking the military stalemate in the Iberian peninsula. The battalion fought at the Battle of Salamanca on 22 July 1812 and took part in the Siege of Burgos from September to October 1812. They then pursued the French Army into France fighting at the Battle of the Pyrenees in July and August 1813, the Battle of Nivelle on 10 November 1813 and the Battle of the Nive in December 1813 as well as the Battle of Orthez in February 1814 and the Battle of Toulouse in April 1814.