Napoleon's confinement on Elba was short lived and on the 1st of March 1815 he escaped from the island and returned to France overthrowing the newly installed monarchy. The old allies immediately declared war on Napoleon and dispatched armies to the Low Countries in preparation for the perceived threat from France. Wellington was appointed Commander in Chief and on the 11th of April the 16th Light Dragoons embarked for the Continent. It was not until June however that Napoleon made his play. On the 16th of June the French advanced on Charleroi where they decisively beat the Prussians who were forced to withdraw. The same day the British faced the mass onslaught of the French at Quatre-Bras and were also forced to withdraw to previously reconnoitred positions at Waterloo. Napoleon had succeeded in driving a wedge between the allied forces.

Napoleon's army pursued Wellington to Waterloo with the armies drawing up into battle lines on the morning of the 18th of June, on what was to be the final and decisive battle of the Napoleonic Wars. The 16th were heavily engaged throughout the day, initially to support the Heavy Brigade under Sir William Ponsonby, which had been ordered to charge retreating French infantry but had pushed the charge too far. As a result, once their horses were blown, they found themselves far from friendly lines and being countered by French lancers as they attempted to rally. It was only the timely intervention of the 16th, which prevented the total destruction of the Heavy Brigade.

With the arrival of the Prussians in the late afternoon Napoleon realised that now outnumbered and out gunned his chances of victory were becoming slim. In a final attempt to break the British he launched his elite Imperial Guard at the British line. The accurate and rapid musketry of the First Guards and 52nd Light Infantry ensured the defeat of the Imperial Guard and the collapse of the French army. It was at this stage that Wellington ordered the general advance and the light cavalry were released to harass the defeated French army.

"No one was ever in such a fight before. I think Bonaparte is ruined. We charged four times. I am not touched, my mare is wounded but not badly." (Cornet Beckwith, 16th Light Dragoons)