The final act of the Napoleonic Wars, the Waterloo campaign took place in Belgium in 1815. It was the military aspect of Napoleon’s attempt to seize power in France and reestablish his empire after his short exile on the Mediterranean island of Elba. This period is also known as the Hundred Days. The Waterloo campaign included the “four-day war,” which featured the action at Charleroi, and the battles of Quatre Bras, Ligny, Waterloo, and Wavre; the race for Paris; the besieging of a number of fortresses in northern France; and the fall of Paris. The military forces directly involved included the Army of the North (Armée du Nord) under the command of Napoleon, the (Prussian) Army of the Lower Rhine under Field Marshal Gebhard Fürst Blücher von Wahlstatt, and an Anglo-Allied army under the Duke of Wellington consisting of contingents from various German states, the Netherlands, and Britain. The Waterloo campaign marked the end of the Napoleonic Wars, with Napoleon being exiled to the island of St. Helena, where he died six years later.
Napoleon’s first abdication had taken place on 6 April at the end of the campaign of 1814. The Bourbons had been restored as the rulers of France, with Louis XVIII becoming king. While much of France breathed a sigh of relief at the end of a long period of warfare, the unemployed soldiers were dissatisfied and restless. The restoration of a dynasty that had not been in power in France for a generation also caused friction. The bitter disputes over the spoils of war between the victorious Allies at the Congress of Vienna did not escape Napoleon’s attention either. Judging the moment right, he left Elba (contrary to popular belief, the Treaty of Paris did not confine him there or ban him from leaving; thus he did not “escape” as is often asserted) with a handful of supporters and landed in the south of France on 1 March 1815. This snowball soon turned into an avalanche that swept Napoleon to Paris and back into power. He owed his success to the support of the army, but the country was divided. Open rebellion broke out in the royalist stronghold in the Vendée.
News of Napoleon’s return reached Vienna a few days later, galvanizing the Allies into action. They declared Napoleon an outlaw and prepared for war, forming the Seventh Coalition. The great powers joining it included Russia, Austria, Britain, and Prussia. Much of the rest of Europe supported the Allies, although Napoleon’s Marshal Joachim Murat, who was concurrently King of Naples, declared for him. The nations of Europe now prepared for the forthcoming conflict. An Austrian army decisively defeated Murat at Tolentino on 2-3 May, while larger forces concentrated along France’s northwestern border.
Napoleon’s forces were so outnumbered that, at least on paper, he did not have a chance. However, he was a gambler and hoped that an early success would cause the fragile coalition to collapse. After all, the erstwhile Allies had all but gone to war with each other in January 1815, and they had different political aims. While Britain sought an equitable balance of power in post-Napoleonic Europe, the Prussians in particular had territorial ambitions that the Vienna settlement had not satisfied. The new Kingdom of the Netherlands, consisting of modern-day Netherlands, Belgium, and Luxembourg, was an unstable mixture of Dutchmen, Flemings, and Walloons, many of whom had been under French rule for the last generation. Here, Napoleon could count on popular support. There were also strong Bonapartist sympathies in Britain, and any military failure might well have led to the fall of the government, led by Lord Liverpool. As Britain was paymaster of the coalition, a change of ministry was likely to cause a change of policy. Napoleon selected the Low Countries as the target for his military adventure.
The Netherlands had been a disputed territory at the Congress of Vienna. It was occupied by both Prussian forces and an Anglo-Allied (British, Dutch, Belgian, and contingents from various small German states) army. On Napoleon’s return to Paris, these forces set about preparing for the forthcoming war. Specifically, they brought in reinforcements and formulated a strategy. The Prussians favored an early intervention in France, but the Anglo-Allies, under Wellington’s command from early April, urged greater caution, wanting both the Austrians and the Russians to join them for an invasion of France. The Prussians wanted to grab as much of the glory as possible for themselves to underline their territorial claims. Wellington wanted to see that the balance of power so carefully established at Vienna was maintained. In any case, the defense of the Netherlands was the priority of the armies based there, and Brussels could not be allowed to fall to Napoleon, as that might well destabilize the Kingdom of the Netherlands. They decided on a defense of that great city to its fore, that is, they resolved to move to meet any invading forces. Against a commander known for his rapid movements, that was a highly risky enterprise.
Napoleon had several choices of routes to Brussels. The shortest way was via Mons, the route Wellington considered he would most likely take. While concentrating his forces along the frontier, Napoleon also undertook a number of movements around Lille, teasing Wellington’s sensitive right and his line of communication via the Channel ports. The Allies needed to spread their forces to cover all eventualities, while Napoleon could concentrate at the point of his choice, achieving a local superiority in numbers. The legal situation here was a little unusual. The Allies recognized the legitimacy of Louis XVIII’s government-in-exile and had declared war on Napoleon, but not France. Accordingly, the border between France and the Netherlands was open. It was business as usual, and the international postal system was operating normally. The Allies were receiving good information from their informants in Paris, who were making use of the post.
This openness made it difficult for Napoleon to achieve the element of surprise, although he later maintained that his invasion astonished the Allies. However, they were aware of the concentration of French forces in the area of Maubeuge, and from 9 June the Allied troops on the frontier were placed on alert. From Maubeuge, Napoleon had two routes to Brussels: that via Mons, where Wellington’s army was waiting for him, or that via Charleroi, where Blücher’s Prussians were in position. While it was clear to all that Napoleon was likely to strike soon, the date was not certain and the route not definite. Napoleon played those doubts to his advantage, remaining in Paris for as long as he could before leaving to join his army. He did so on 13 June, the Allies hearing this news only hours later. During the course of the next day, it became evident that hostilities were going to commence the coming morning and that the line of attack was going to be via Charleroi. Wellington had already assured the Prussians that in such an eventuality he would move to their support.
