The leader of the British during the Battle of Waterloo was the Duke of Wellington, Arthur Wellesley. He commanded Allied forces against Napoleon Bonaparte's French army in this decisive battle on June 18, 1815. The Duke’s strategic leadership and ability to coordinate with Prussian forces, led by Gebhard Leberecht von Blücher, played a crucial role in ensuring a victory that ultimately led to Napoleon’s downfall and the restoration of peace in Europe.