The regiment, called at the time the Royal Newfoundland Regiment of Fencible Infantry, was significantly involved in the War of 1812. In May 1812, weeks before outbreak of the war with the United States, Major-General Sir Isaac Brock, commander of his Majesty's Forces in Upper Canada, deployed the regiment into smaller companies or detachments, combined with other units or regiments in defensive positions all over the province. Some were employed as marines on board naval vessels on the Great Lakes as part of the Provincial Marine. These marines were involved in a number of notable naval actions during the war, including the Battle of Lake Erie and the capture of USS "Tigress" and USS "Scorpion".