On February 25th, 1812, the cadre of the 2nd Battalion 52nd, having transferred 500 men to the 1st Battalion, left the Light Division in the field to proceed to England.
Early in March, the division moved south for Badajoz, the strongest fortress on the Spanish frontier, now, for the third time, besieged by Lord Wellington's Army.
After successful minor operations, the night of April 6th was ordered for the assault. Here the gallantry and self-sacrifice of the Regimental officers and men, which alone turned what was nearly a failure into a success, and the very heavy casualties, made the storming of Badajoz memorable for all time. The 43rd lost their Colonel, Macleod, shot dead in leading a charge, 19 other officers, and 335 other ranks, the 52nd 19 officers and 334 others.
Four days later the Army again moved north, and from April 25th to June 11th was in billets to the south of Ciudad Rodrigo. On June 16th the forward march was resumed, in the direction of Salamanca, where a battle was fought on July 22nd. The Light Division, having been one of those in reserve, was at evening sent hurriedly to bar the passage of the river, and cut off the retreating French. Owing to the carelessness of the Spanish troops, the movement was only partially successful, but on the next day the Light Division led the pursuit and soon overtook the enemy's rearguard, taking some hundreds of prisoners. The main army, however, made good its retreat.
Having prevented the junction of the two French armies, Lord Wellington occupied Madrid, in which area the 43rd and 52nd remained, until on October 31st he began his return march across the Guadarame Mountains, with the Cavalry and Light Division as rearguard.
In November the conditions of the retreat somewhat resembled those of the Corunna campaign; on November 17th a sharp action was fought at San Munoz, where the rearguard was caught in the open and heavily shelled. At the end of this month the division went into winter quarters in the villages to the south of Ciudad Rodrigo.
For nearly six months the 43rd and 52nd enjoyed comparative comfort and rest: amusements, including a divisional theatre at Gallegos, being provided; after which came preparations for the summer offensive, and the end of May, 1813, saw the Light Division on the Salamanca road, following the retreating French via Burgos and Vittoria towards France. On June 18th there was a sharp fight at San Milan, and three days later, in rain and heat, the Battle of Vittoria was fought, darkness alone saving the remnant of the French Army.
From July 25th to August 2nd were fought the Battles of the Pyrenees, which for the Light Division meant a great deal of marching and counter-marching to and from threatened points. Meanwhile San Sebastian was besieged by the main army, but by the end of July the siege had become a mere blockade, on account of Lord Wellington's shortage of men, guns, and stores. The latter arriving near the end of August, siege operations were resumed, and volunteers were called for from the tight Division and other troops who had not formed part of the investing force. The stormers of the division, instead of being allowed to lead the assault, which began in broad daylight, about 11 a.m., were used to keep up covering fire from the trenches, whence, however, they advanced early in the afternoon to the Greater Breach, in time to be able to play their proper part in the attack. Of the storming parties of the 43rd and 52nd, more than half, and all the officers, became casualties, but the assault was successful.
On October 7th, in the attack on the heights of Vera, following the passage of the Bidassoa, a swift counter-charge by the 52nd at one moment saved the situation. On November l0th the 43rd similarly distinguished themselves at the Battle of the Nivelle. The next day Lord Wellington advanced, his progress somewhat hindered by bad weather, and on December 9th and following days the 43rd and 52nd took part in the operations leading up to the Battle of the Nive on the 13th. The Light Division went into winter quarters near Arcangues.
On December 9th also, the 2nd Battalion 52nd embarked at Ramsgate for Holland, as part of a light brigade under Major General Mackenzie, who had commanded the Regiment in 1803.
The campaign of 1814 opened in February, and on the 27th the Battle of Orthes was fought. Here the Light Division (less the 43rd and 1st Battalion 95th, who were refitting in rear), took a prominent part, the 52nd being specially mentioned by Lord Wellington. The next victory at Tarbes, on March 20th, drove the French to Toulouse, which was attacked on April 10th, but evacuated by the French on the 11th. This practically ended the war.
In June orders came for embarkation for England, and the Portuguese Brigade of the Light Division returned home. Writing of this parting, which meant the breaking up of the division, Sir John Colborne described it as "a very affecting scene," when the brigade marched away, passing through the ranks of the 43rd, 52nd, and 95th, who then embarked at Bordeaux.