The 7th played an important role in both the Battles of Quatre Bras and Waterloo, where Napoleon Bonaparte was finally defeated by the Anglo-allied army commanded by the Duke of Wellington and the Prussians under Prince Blucher. As a part of the 1st "Brigade van Bylandt" the Battalion first saw action at Quatre Bras on 16 June 1815, to counter the advance of the French Army. Two days later, on 18 June, during the Battle of Waterloo it had to endure the first massive attack by the French I Corps commanded by d'Erlon. When the Brigade had to withdraw through sheer weight of numbers, the 7th was able to hold up the French I Corps long enough for the neighbouring British 8th and 9th brigades to move in to fill the gaps. Even though the entire Brigade van Bylandt received heavy losses, they would remain in place for the entire battle.