Once Napoleon escaped from the island of Elba where he had been sent into exile, he convinced the Assembly to regain the empire. Upon hearing this, all the countries that were against Napoleon set up the Seventh Coalition in order to defeat him with six armies of potentially one million men. If Napoleon had waited for the coalition to attack, they would have overwhelmed the French easily and so he chose to attack each army before they could unite. Therefore he travelled up to Belgium, with 122 000 men, where the armies were about to unite. Having beaten a Prussian Army commanded by Gebhard von Blücher, in the Battle of Ligny and having drawn with the British in the battle of Quatre Bras on the same day, he had to now face the most important battle of his life … the Battle of Waterloo on the 18th June.
Planning to start the battle on the 17th June 1815, he was forced to start it the following day as on the 17th June it rained heavily. This was to prove decisive as not only did it allow the Prussians more time to come, from Wavre, to reinforce the Anglo-allied armies with over 60000 men but the weather affected the French artillery as canons would be less affective because they would just lay on the muddy surface. The French started the battle with 70 000 men whilst the Anglo-allied armies had 90 000 men which were from the U.K, Hanover, Nassau, Brunswick and the Netherlands.
Napoleon divided his army into a left wing, a right wing and a reserve (which he would control personally). The left wing was to be commanded by Marshal Michel Ney and the right wing was to be commanded by the French Marshal Marquis Emmanuel de Grouchy.
At the beginning of the day, Wellington wrote letters to Gebhard von Blücher, the Prussian army commander, asking him to give him some soldiers to take on Napoleon's army.
Blücher sent his chief of staff, August Graf Neidhardt von Gneisenau, to march to Waterloo to provide back up for Wellington with potentially 50 000 men because Blücher had to fight in the Battle of Wavre.
The battle began in the late morning, with a French attack on Hougoumont, a large farmhouse which the British Coldstream guards had control of. The French wanted this farmhouse as it was like a "fortress" but also it overlooked a very important road that could have been very useful. Moreover, the aim of the attack on Houghoumont was to draw Wellington's reserves into it but instead it drew Napoleon's reserves and 14 000 troops. Napoleon got so frustrated that he personally ordered it to be set on fire. It is true to say that Houghoumont had a big impact on the battle as it caused Napoleon to send his troops there when they could have proved to be useful in the actual battle.
Shortly after midday, the 80 guns of Napoleon's grande batterie made their way into the centre of the battlefield and opened fire. However, there were many ridges in the battlefield and so Wellington ordered his men to stay behind them and use the “reverse slope defence”. This was a tactic, which made all Wellington's men hide under a hill so that Napoleon could not kill them with his grande batterie. However, he could still see a Dutch division that had not followed Wellington's orders so he fired but as the ground was wet, his cannonballs did less damage. More bad news came when Napoleon saw over 50 000 Prussians near the village of Chapelle St Lambert which was around three hours march from where Napoleon was. Napoleon had told Marshal Grouchy to follow the Prussians to Wavre "with swords against his back". Napoleon thought that Marshal Grouchy would have been aware that there were some Prussians coming towards the battlefield and so sent his messenger to tell him to come to Waterloo and attack the Prussians. However, Grouchy was too far from Waterloo and because he was executing Napoleon's first orders he didn't follow the Prussians and instead attacked the remaining Prussians at Wavre.
At the other side of the battlefield, D'Erlon, who was in charge of four divisions, ordered his first division to attack and with the help of the Cuirassiers, French mounted cavalry, they managed to isolate Hougoumont which caused the Prince of Orange to send a Hanoverian Battalion to reinforce it but the Cuirassiers easily killed them. D'Erlon got all his 14 000 men in his four divisions to attack Wellington's weak left wing, commanded by Sir Thomas Picton. They faced 6,000 men: the first line consisted of the Dutch 2nd division, the second of British and Hanoverian troops under Sir Thomas Picton were lying down in dead ground behind the ridge. D'Erlon easily defeated the Dutch 2nd Division and went up the ridge to crush the remaining men but to their surprise they opened fire but the French did not panic and returned fire. Due to being outnumbered, Picton and his men died.
