Two new battalions were raised in late 1804, at Hamilton, the 3rd and 4th Battalions. The 3rd served in the Peninsular War from 1808 to 1809, fighting at the Battle of Corunna in 1809 before being withdrawn by sea and sent to the Walcheren Campaign with the 1st Division. It returned to Portugal in 1810 with the 5th Division, fighting at the Battle of Buçaco (1810), the Battle of Fuentes de Onoro (1811), the battles of Badajoz, Salamanca and Burgos (1812), the Battle of Vitoria, capture of San Sebastián, Battle of Nivelle, and the Battle of Nive (1813), before advancing into France in 1814. It was sent to Belgium during the Hundred Days, and fought in Picton's Division (the 5th) at the Battle of Waterloo (1815). After two years in the Army of Occupation, it was disbanded at Canterbury in 1817.