Louis fought with the regiment at the Battle of Maida, in 1806, and at the Siege of Cádiz. He was appointed Colonel of his regiment in 1812. In the following year, he and the regiment were transferred from Cadiz to Upper Canada. By this time the regiment was a mixture of nationalities, including German, Italian and Hungarian, many of whom had been taken prisoner of war by the British while serving in the French armies in Spain.