Battle of Waterloo (1815). The Battle of Waterloo was fought on Sunday, 18 June 1815 near Waterloo in Belgium, part of the United Kingdom of the Netherlands at the time. A French army under the command of Napoleon Bonaparte was defeated by two of the armies of the Seventh Coalition: an army consisting of units from Britain, Ireland, the German Legion, the Netherlands, Hanover, Brunswick and Nassau, under the command of the Duke of Wellington, referred to by many authors as the Anglo-allied army, and a Prussian army under the command of Field Marshal Blücher. The battle marked the end of the Napoleonic Wars. Upon Napoleon's return to power in March 1815, many states that had opposed him formed the Seventh Coalition and began to mobilise armies. Wellington and Blücher's armies were cantoned close to the northeastern border of France. Napoleon chose to attack them separately in the hope of destroying them before they could join in a coordinated invasion of France with other members of the coalition. On 16 June, he successfully attacked the bulk of the Prussian army at the Battle of Ligny with his main force, while a portion of the French army simultaneously attacked an Anglo-allied army at the Battle of Quatre Bras. Despite holding his ground at Quatre Bras, the defeat of the Prussians forced Wellington to withdraw north to Waterloo on the 17th. Napoleon sent a third of his forces to pursue the Prussians, who had withdrawn parallel to Wellington in good order. This resulted in the separate and simultaneous Battle of Wavre with the Prussian rear-guard. 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. Here he withstood repeated attacks by the French throughout the afternoon of the 18th, aided by the progressively arriving Prussians. In the evening, Napoleon committed his last reserves, the senior battalions of the French Imperial Guard infantry. The desperate final attack of the Guard was narrowly beaten back. With the Prussians breaking through on the French right flank, Wellington's Anglo-allied army counter-attacked in the centre, and the French army was routed. Waterloo was the decisive engagement of the Waterloo Campaign and Napoleon's last. 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 ended Napoleon's rule as Emperor of the French and marked the end of his Hundred Days return from exile. This ended the First French Empire and set a chronological milestone between serial European wars and decades of relative peace. The battlefield is located in the municipalities of Braine-l'Alleud and Lasne, about 15 kilometres south of Brussels, and about 2 kilometres from the town of Waterloo. The site of the battlefield today is dominated by the monument of the Lion's Mound, constructed from earth taken from the battlefield itself; the topography of the battlefield near the mound has not been preserved. Main article: Waterloo Campaign On 13 March 1815, six days before Napoleon reached Paris, the powers at the Congress of Vienna declared him an outlaw. Four days later, the United Kingdom, Russia, Austria, and Prussia mobilised armies to defeat Napoleon. Critically outnumbered, Napoleon knew that once his attempts at dissuading one or more members of the Seventh Coalition from invading France had failed, his only chance of remaining in power was to attack before the coalition mobilised. Had Napoleon succeeded in destroying the existing coalition forces south of Brussels before they were reinforced, he might have been able to drive the British back to the sea and knock the Prussians out of the war. Crucially, this would have bought him time to recruit and train more men before turning his armies against the Austrians and Russians. An additional consideration for Napoleon was that a French victory might cause French-speaking sympathisers in Belgium to launch a friendly revolution. Also, coalition troops in Belgium were largely second-line, as many units were of dubious quality and loyalty, and most of the British veterans of the Peninsular War had been sent to North America to fight in the War of 1812. The initial dispositions of British commander Arthur Wellesley, 1st Duke of Wellington, were intended to counter the threat of Napoleon enveloping the Coalition armies by moving through Mons to the south-west of Brussels.