In 1811 the brigade was in the advance guard in following the enemy up to his position at Santarem; was at the out-posts there, and again in the advance on the further retreat of the French from Portugal. It was employed in the investment of Almeida, and in the operations against Marshal Marmont, on his advance to the relief of Ciudad Rodrigo in January 1812. At the siege of Ciudad Rodrigo it bore a distinguished part. It marched to the siege of Badajos, and was in active operations against the enemy on his advance to the Tagus, and subsequent retreat from Portugal. It moved in the advanced guard on the march of the allies to Salamanca and the Douro. It suffered severely in the battle of Salamanca on the 22d of July 1812. The brigade was in the march to and capture of Madrid; in the march to Burgos, and subsequent siege of that place. Previously to the siege of Burgos, detachments under Colonel Pack’s command carried by assault the horn-work of that castle, after a desperate and gallant action, for which the special thanks of His Royal Highness the Prince Regent, and the Commander-in-Chief, were given to the troops, through the Marquis of Wellington. In the retreat from Burgos, which commenced in October 1812, the brigade under Colonel Pack formed the rear-guard, and from thence to the frontier of Portugal was very frequently in presence of the enemy. In the memorable advance of the Marquis of Wellington into Spain, in May 1813, and the passage of the Ebro, the brigade was in the advanced guard of the left column of the army under Lieut.-General Sir Thomas Graham, afterwards Lord Lynedoch. It was in the battle of Vittoria, fought on the 21st of June 1813, and again in the advance of Lieut.-General Sir Thomas Graham’s corps, in the pursuit of the French to the Bidassoa. Shortly afterwards, Major-General Pack, to which rank he was advanced on the 4th of June 1813, was appointed to the _Highland_ brigade in the sixth division; the division at this time for a short period was also under his command, and after a forced march he arrived in time to share in the victory gained by the Marquis of Wellington over the French under Marshal Soult near Pampeluna, on the 30th of July 1813, in which action Major-General Pack was severely wounded in the head. He commanded the Highland brigade in the passage of the Bidassoa, and advance of the British into France; in the overthrow of the enemy in his fortified lines before Bayonne; the advance to and passage of the Nive; the repulse of the enemy’s attack on the British position before St. Jean de Luz; and, though not actually engaged, he was present at the signal defeat of the enemy’s desperate attack on Lieut.-General Sir Rowland Hill’s corps on the 13th of December 1813. Major-General Pack was also in the passage of the Bidassoa, the Gave D’Oleron, and the Pau; at the battle of Orthes on the 27th of February 1814; in the passage of the Adour at St. Seur, and at the battle of Toulouse on the 10th of April