Only three months before, Napoleon had slipped away from his island prison of Elba off the western coast of Italy. When he returned to France his veteran soldiers flocked to rejoin him. He hurried northward, hoping to defeat his enemies before they could unite against him.
Napoleon's plan was to get between the British and Dutch, who were grouped near Brussels, and the Prussians, who were east of the road from Charleroi to Brussels. On June 16 French Marshal Michel Ney engaged the British at Quatre Bras, while Napoleon crushed--as he thought--Field Marshal Gebhard L. von Blücher's Prussians at Ligny. After these battles Napoleon ordered Marshal Emmanuel de Grouchy to follow the Prussians, and Napoleon turned his attention to the British. Blücher, however, marched northward to the assistance of the duke of Wellington, the British commander, while Grouchy wasted valuable time looking for the Prussians east of Ligny. It was at this point that Napoleon's plans began to fall apart. The essence of his original strategy was surprise. The battle of Ligny was indecisive because Marshal Ney had failed to send reinforcements that could have crushed the Prussian army. Then Napoleon made the false assumption that Blücher would retreat to the northeast instead of heading northwest to link up with Wellington. Lastly, the element of surprise was completely lost when Napoleon wasted the night of June 16 and the morning of the 17th without giving battle. By the time he started, Wellington was ready for him.
The British, meanwhile, retreated from Quatre Bras to the village of Waterloo. Napoleon overtook them late on June 17. Because of the heavy rain that night, he could not attack until the next morning. His artillery could not move until the ground dried. He delayed the attack until 11:00 AM.
The ensuing battle raged for ten hours. Napoleon repeatedly threw his cavalry against the bayonet-wielding British infantry. During one furious cavalry charge the French overran all the British artillery. Had the guns been destroyed or at least made unusable at that time, the French cavalry might have won the battle. For a time it looked as though the British ranks would give way under the onslaught.
Wellington eagerly awaited the help the Prussians had promised. Finally, late in the afternoon, Blücher and his men arrived. Those few hours of delay in the morning had been decisive. The French made a last desperate attack but were slowly overcome. By 9:00 PM the French defeat had become a rout. Napoleon lost 25,000 men killed and wounded and 9,000 captured. Wellington's casualties were 15,000 and Blücher's about 8,000.
On June 22, 1815, four days after the battle of Waterloo, Napoleon signed his second abdication in Paris. This ended his rule in France forever.