During the Seven Years' War, a battalion of the regiment took part in several battles including Fort Saint Frédéric on Lake George (September 1755), and the taking of Fort Bull and Fort William-Henry. Their greatest victory came at Fort Carillon in 1758 against the forces of General Abercromby. They were then sent to Isle aux Noix in July of that same year, and were absent from the Battle of the Plains of Abraham the following year. However, they did take part at the Battle of Sainte-Foy in 1760, where the British under General Murray were defeated. At the subsequent siege of Quebec they were unable to subdue the British and had to retreat to Montreal in May. They could not fend off the British three pronged attack against Montréal in September and surrendered there.