Battle of Wagram

The Battle of Wagram was one of the largest engagements of the Napoleonic Wars, pitting the forces of Napoleon I against the Austrian army commanded by Archduke Charles. After suffering a reverse at Aspern-Essling, Napoleon crossed the Danube again in early July 1809 with the help of a vast pontoon bridge built in secret. On 5 July the French army was attacked while still deploying, but held against the assaults. The next day Napoleon organized a decisive counter-offensive, supported by a massive concentration of artillery in the center (the "grand battery") and a powerful attack on the right flank led by Marshal Davout. Archduke Charles, unable either to break the French lines or contain their coordinated attacks, ordered a retreat on the evening of 6 July. This victory allowed Napoleon to impose severe terms on Austria.

In 1809 the Austrian Empire took advantage of the French entanglement in Spain and the fragility of Napoleon's position after the 1808 campaign to reopen the war. Austria formed the Fifth Coalition with the United Kingdom and mobilized a modernized army under Archduke Charles. After a series of engagements in Bavaria and the French capture of Vienna, Napoleon attempted a crossing of the Danube but suffered a partial defeat at Aspern-Essling (May 1809), his first real military setback. He drew logistical and strategic lessons from it: he strengthened the bridgeheads and built extensive floating infrastructure between Lobau Island and the left bank of the Danube. In early July he succeeded in moving more than 150,000 men and nearly 500 guns onto the Marchfeld plain, facing Archduke Charles's 140,000 men. Wagram thus became, at that moment, the largest and bloodiest battle of the Napoleonic era.

Napoleon initially adopted an extended defensive posture over more than 10 kilometers, in an arc around Lobau Island. The French army was divided into several corps distributed between Davout on the far right, Oudinot, Bernadotte (Saxons), Masséna on the left, and Eugène de Beauharnais on the center-left. The Austrian attack of 5 July concentrated on the junction between still-deploying French forces, but the lines held. On 6 July Napoleon launched a counter-offensive: the grand battery, grouping about 100 guns, pounded the Austrian center to create a breach. Simultaneously Davout attacked strongly on the Austrian left near Neusiedel, while Masséna, despite his wounds, executed a turning maneuver with his troops on the enemy left flank. Bessières's cavalry and the Imperial Guard intervened to stabilize the center. The combined action of artillery, infantry, and cavalry drove back the Austrians. Archduke Charles, lacking coordination between his columns and refusing to risk the annihilation of his army, ordered an orderly retreat covered by cavalry and artillery.

The victory at Wagram compelled Austria to sign the Treaty of Schönbrunn (14 October 1809), which entailed major territorial losses: Austria ceded western Galicia to Poland (Duchy of Warsaw), territories to Bavaria, Russia, and France (the Illyrian Provinces). The French Empire then reached its territorial zenith. The victory temporarily reinforced Napoleon's military prestige, but also revealed the limits of the imperial system: the human cost (nearly 70,000 men in two days) caused shock, and the mobilization of foreign troops (notably Saxons and Italians) underscored Napoleon's growing dependence on his allies. Moreover, although defeated, Austria was not definitively crushed and remained a major power. It was the last great Napoleonic victory on this scale before the turning point of the Russian campaign in 1812. It also marked the end of Archduke Charles's active career as commander-in-chief.