Category: History
Question: During this battle, Marshal Ney led a cavalry assault that was turned back by infantry squares on the road to Brussels. It ended with the repulse of an attack by grenadiers of the Imperial Guard and the arrival of Blucher's (“BLUE-kers”) Prussian army, which saved a combined force of Dutch and British led by the Duke of Wellington. For 10 points, name this 1815 battle, the final defeat of Napoleon.
Answer: Battle of {Waterloo}

The Battle of Waterloo (Dutch pronunciation: [ˈʋaːtərloː] ) was fought on Sunday 18 June 1815, near Waterloo (at that time in the United Kingdom of the Netherlands, now in Belgium), marking  the end of the Napoleonic Wars. A French army under the command of Napoleon was defeated by two armies of the Seventh Coalition. One of these was a British-led force with units from the United Kingdom, the Netherlands, Hanover, Brunswick, and Nassau, under the command of the Duke of Wellington (often referred to as the Anglo-allied army or Wellington's army). The other comprised three corps (the 1st, 2nd and 4th corps) of the Prussian army under Field Marshal Blücher; a fourth corps (the 3rd) of this army fought at the Battle of Wavre on the same day. The battle was known contemporarily as the Battle of Mont Saint-Jean in France (after the hamlet of Mont-Saint-Jean) and La Belle Alliance in Prussia (means "the Beautiful Alliance"; after the inn of La Belle Alliance).
Upon Napoleon's return to power in March 1815 (beginning the Hundred Days), many states that had previously opposed him formed the Seventh Coalition and hurriedly mobilised their armies. Wellington's and Blücher's armies were cantoned close to the northeastern border of France. Napoleon planned to attack them separately, before they could link up and invade France with other members of the coalition.
On 16 June, Napoleon successfully attacked the bulk of the Prussian army at the Battle of Ligny with his main force, while a small portion of the French army contested the Battle of Quatre Bras to prevent the Anglo-allied army from reinforcing the Prussians. The Anglo-allied army held their ground at Quatre Bras, and on the 17th, the Prussians withdrew from Ligny in good order, while Wellington then withdrew in parallel with the Prussians northward to Waterloo on 17 June. Napoleon sent a third of his forces to pursue the Prussians, which resulted in the separate Battle of Wavre with the Prussian rear-guard on 18–19 June, and prevented that French force from participating at Waterloo.
Upon learning that the Prussian Army was able to support him, Wellington decided to offer battle on the Mont-Saint-Jean escarpment across the Brussels road, near the village of Waterloo. Here he withstood repeated attacks by the French throughout the afternoon of 18 June and almost lost the battle, but was eventually aided by the progressively arriving 50,000 Prussians who attacked the French flank and inflicted heavy casualties. In the evening, Napoleon assaulted the Anglo-allied line with his last reserves, the senior infantry battalions of the Imperial Guard. With the Prussians breaking through on the French right flank, the Anglo-allied army repulsed the Imperial Guard, and the French army was routed.
Waterloo was the decisive engagement of the Waterloo campaign and Napoleon's last. It was also the second bloodiest single day battle of the Napoleonic Wars, after Borodino. According to Wellington, the battle was "the nearest-run thing you ever saw in your life". Napoleon abdicated four days later, and coalition forces entered Paris on 7 July. The defeat at Waterloo marked the end of Napoleon's Hundred Days return from exile. It precipitated Napoleon's second and definitive abdication as Emperor of the French, and ended the First French Empire. It set a historical  milestone between serial European wars and decades of relative peace, often referred to as the Pax Britannica.  In popular culture, the phrase "meeting one's Waterloo" has become an expression for someone suffering a final defeat.
The battlefield is located in the Belgian municipalities of Braine-l'Alleud and Lasne, about 15 kilometres (9.3 mi) south of Brussels, and about 2 kilometres (1.2 mi) from the town of Waterloo. The site of the battlefield today is dominated by the monument of the Lion's Mound, a large artificial hill constructed from earth taken from the battlefield itself, but the topography of the battlefield near the mound has not been preserved.