The Battle of Leipzig, also known as the Battle of the Nations, was the largest battle of the Napoleonic Wars and the largest battle fought in Europe prior to World War I. The Coalition armies of Austria, Prussia, Sweden, and Russia decisively defeated the multinational army of French emperor Napoleon in Germany in a battle involving 560,000 soldiers, 2,200 artillery pieces, and 133,000 casualties.
After the failed French invasion of Russia, Prussia, Russia, and Sweden (soon to be joined by Austria) formed a Sixth Coalition against France, and Napoleon's former marshal Jean-Baptiste Bernadotte - by then Crown Prince of Sweden - conceived a plan to avoid battle with Napoleon and defeat his marshals in isolation. This Trachenberg Plan resulted in victories at Grossbeeren, Kulm, Katzbach, and Dennewitz, and rising German nationalism led to the mutinying of Saxon and Westphalian armies fighting for France. In September, Bavaria declared neutrality, and Napoleon's thinly-stretched supply lines and Bavaria's betrayal made it almost impossible for Napoleon to replace his 150,000 losses on the eve of his confrontation with the Coalition at Leipzig. As Prussian armies threatened him from Berlin and the Elbe, Napoleon withdrew to Leipzig to protect his supply lines and organized his forces around the city.
The Prussians advanced from Wartenburg, the Austrians and Russians from Dresden, and the Swedes from the north. Napoleon's army included 160,000 French soldiers (most of them teenagers and inexperienced conscripts), 15,000 Poles, 10,000 Italians, and 40,000 Germans belonging to the Confederation of the Rhine. The Coalition had 145,000 Russian soldiers, 115,000 Austrians, 90,000 Prussians, and 30,000 Swedes. Napoleon planned to take the offensive between the Pleisse and Parthe rivers, and he could shift troops from one sector to another via Leipzig's bridges. The battle began on 16 October, and the French fought the Allies to a draw on the first day, inflicting 30,000 casualties and losing 25,000 men. Jean Reynier's 14,000 men reinforced Napoleon's army to 200,000, but the Allies soon received 70,000 reinforcements from Bernadotte and a similar number from Levin August von Bennigsen. On the second day, the Russian general Fabian Gottlieb von der Osten-Sacken overwhelmed Jan Henryk Dabrowski's Polish division at the village of Gohlis, and the Allied cavalry overwhelmed General Jean-Toussaint Arrighi de Casanova's III Cavalry Corps. By 18 October, the arrival of Allied reinforcements threatened to encircle Napoleon's army, which was running low on ammunition. Napoleon remained determined to fight and secure a victory rather than save his army by withdrawing, but the allies launched a huge assault from all sides and completely encircled Napoleon's army. Both sides suffered heavy losses as the French were forced back towards Leipzig. At Probstheida, 60,000 Allied soldiers assaulted a village where French soldiers took cover behind thick garden walls and heavy fortifications. The French withstood numerous attacks before the Imperial Guard arrived and reinforced them. Meanwhile, Bernadotte's overtures to the German soldiers in the Napoleonic army resulted in the defection of 5,400 Saxons of Reynier's VII Corps, and Wurttemberg's cavalry also deserted from the French. 18 October saw the French hold onto their respective positions, although they were steadily worn out and depleted by fierce and intensifying Allied attacks throughout the day. Napoleon promoted Prince Jozef Poniatowski to the rank of Marshal of the Empire, and Poniatowski vowed to fight to the death. The French proceeded to engage in a fighting withdrawal, and the French retreated across the Elster river before blowing its bridges. Poniatowski, hampered by battle wounds, drowned while attempting to cross the river to safety. By the afternoon of 19 October, the remnants of the Grande Armee had escaped.
The Battle of the Nations ended the French Empire's presence east of the Rhine and brought Baden, Saxony, and Wurttemberg over to the Coalition. Three weeks later, Napoleon returned to Saint-Cloud and worked to organize the defense of France, declaring to the Conservative Senate, "A year ago all Europe marched with us; today all Europe marches against us." In early 1814, Coalition armies invaded France, and Paris fell on 31 March; Napoleon was forced to abdicate on 6 April.