The Battle of Waterloo, fought on June 18, 1815, near the village of Waterloo in the United Kingdom of the Netherlands (present-day Belgium), was a decisive conflict that ended the Napoleonic Wars. The battle pitted the French army, led by Napoleon Bonaparte, against two powerful forces from the Seventh Coalition. One of these was a British-led coalition under the command of the Duke of Wellington, which included troops from the United Kingdom, the Netherlands, Hanover, Brunswick, and Nassau. The other force was a larger Prussian army commanded by Field Marshal Gebhard Leberecht von Blücher. Together, these forces effectively crushed Napoleon's ambitions and marked the final chapter in his reign. The battle was also known as the Battle of Mont Saint-Jean (to the French) or La Belle Alliance (to the Prussians).

The events leading to Waterloo began when Napoleon returned to power in March 1815, following his exile to the island of Elba. His return prompted his former enemies to form the Seventh Coalition, a group determined to prevent his resurgence. The British and Prussian armies were stationed along France's northern border, preparing for a possible confrontation. Napoleon, keen to defeat his enemies before they could join forces, planned to strike at each army individually. On June 16, he attacked the Prussian army at the Battle of Ligny, inflicting a significant defeat, which forced the Prussians to retreat northward. However, the Prussian retreat was conducted in good order, and they maintained contact with Wellington's forces, who were stationed nearby.