They took part in the Capture of Fort Oswego in August of that same year and then escorted the British prisoners to Montreal after the battle.
The Regiment played a key role in the victory at Fort Oswego and lost seven men in the process.
At Fort William Henry, the Regiment contributed 800-900 men of the roughly 5000 who fought in the battle itself.
The next battle in which La Sarre took part was the decisive British victory at the Planes of Abraham.
There were signs of retreat on the left, but the Regiment fought bravely and held off the British forces for half an hour until the rest of the French Army came to its aid.
Eventually, the Regiment, with the help of the rest of the French Army, managed to push the enemy off the battlefield.
In the following months, the French were on a constant retreat and could not fend off the British three-pronged attack on Montreal.