Wellington commanded approximately 68,000 troops at Waterloo. The frequently cited figure is about 67,655 men in the Anglo-allied force that held the defensive position on 18 June 1815.
This multinational army included British, Dutch-Belgian, Hanoverian, Brunswick, Nassau, and King’s German Legion troops. Only about 28 percent were British; the rest came from allied and German states. Wellington’s army also included roughly 156 guns, with cavalry and infantry positioned across the ridge near Mont-Saint-Jean.
The number can look smaller or larger depending on what a historian means by “Wellington’s army.” Wellington had additional troops stationed at Halle, west of the battlefield, and the Prussian army that arrived during the battle was a separate Coalition force under Blücher. Those troops should not simply be added to Wellington’s command.
Wellington used the ridge, reverse slopes, fortified farms such as Hougoumont and La Haye Sainte, and disciplined infantry formations to withstand repeated French attacks. The combined Anglo-allied and Prussian effort ultimately defeated Napoleon’s larger force.