The Battle of Wagram ([ˈvaɡram]; 5–6 July 1809) was a military engagement of the Napoleonic Wars that ended in a costly but decisive victory for Emperor Napoleon's French and allied army against the Austrian army under the command of Archduke Charles of Austria-Teschen. The battle led to the breakup of the Fifth Coalition, the Austrian and British-led alliance against France. Wagram was the largest battle in European history up to that time.
In 1809, the French military presence in the Confederation of the Rhine was diminished as Napoleon transferred a number of soldiers to fight in the Peninsular War. As a result, the Austrian Empire saw its chance to recover some of its former sphere of influence and invaded the Kingdom of Bavaria, a French ally. Recovering from his initial surprise, Napoleon beat the Austrian forces and occupied Vienna at the beginning of May 1809. Despite the string of sharp defeats and the loss of the empire's capital, Archduke Charles salvaged an army, with which he retreated north of the Danube. This allowed the Austrians to continue the war. Towards the end of May, Napoleon resumed the offensive, suffering a surprise defeat at the Battle of Aspern-Essling.
It took Napoleon six weeks to prepare his next offensive, for which he amassed a French, German and Italian army of over 150,000 men in the vicinity of Vienna. The Battle of Wagram began after Napoleon crossed the Danube with the bulk of these forces during the night of 4 July and attacked the Austrian army, which had over 130,000 men. Having successfully crossed the river, Napoleon attempted an early breakthrough and launched a series of evening attacks against the Austrian army. The Austrians were thinly spread in a wide semicircle, but held a naturally strong position. After the attackers enjoyed some initial success, the defenders regained the upper hand and the attacks failed. Bolstered by his success, the next day at dawn Archduke Charles launched a series of attacks along the entire battle line, seeking to take the opposing army in a double envelopment. The offensive failed against the French right but nearly broke Napoleon's left. However, the Emperor countered by launching a cavalry charge; the Austrian battalion-sized, tightly packed column formation (literally a square; mass), suitable for the multitude of hastily trained Austrian soldiers, held off the attack, but this temporarily halted the Austrian advance. Bonaparte then redeployed IV Corps to stabilise his left, while setting up a grand battery, which pounded the Austrian right and centre. The Austrians used "lie down" tactics to reduce losses from artillery. In the battle, there was also an action when a battalion of Austrian jäger took cover in a drainage ditch 100 paces in front of Deutsch-Wagram; when the French columns marched toward this village the well-drilled jäger rose up and delivered a volley at close range, similar to what the coalition did at Waterloo 6 years later. The tide of battle turned, despite the Austrians' resilience. The Emperor, with his superior numbers, launched an offensive along the entire line. Maréchal Louis-Nicolas Davout drove an offensive which turned the Austrian left and rendered Charles's position untenable, despite the failure of Général Macdonald's attack. Towards mid-afternoon on 6 July, Charles admitted defeat and led a retreat, frustrating enemy attempts to pursue. After the battle, Charles remained in command of a cohesive force and decided to retreat to Bohemia. However, the Grande Armée eventually caught up with him and scored a victory at the Battle of Znaim. With the battle still raging, Charles decided to ask for an armistice, effectively ending the war.
The two-day battle of Wagram was particularly bloody, mainly due to the extensive use of artillery on a flat battlefield packed with some 300,000 men. Although Napoleon was the uncontested winner, he failed to secure an overwhelming victory and the Austrian casualties were only slightly greater than those of the French and allies. Nonetheless, the defeat was serious enough to shatter the morale of the Austrians, who could no longer find the will to continue the struggle. The resulting Treaty of Schönbrunn meant the loss of one sixth of the Austrian Empire's subjects, along with some territories, rendering it landlocked until the German Campaign of 1813.
After the battle, Emperor Napoleon bestowed on Louis-Alexandre Berthier, who was his Marshal, Chief of Staff, Minister of War and Vice-Constable of the Empire, the victory title of 1st Prince of Wagram, making him an official member of the French nobility. Berthier had previously been granted the title of Sovereign Prince of Neuchâtel and the Prince of Valangin in 1806. This allowed his descendants to carry the titles of Prince and Princess of Wagram.
In 1809, the First French Empire held a dominant position on the European continent. Resounding victories during the 1805 to 1807 wars against the Third and Fourth coalitions had ensured almost undisputed continental hegemony, to such an extent that no other European power could challenge the might of Napoleon's empire. However, despite having defeated Austria, forced Russia into an uneasy alliance and reduced Prussia to the rank of a second-rate power, Napoleon did not manage to force the United Kingdom to make peace. With the British in complete control of the seas, Napoleon thus opted for an economic war, imposing the Continental System against the British Isles, in a bid to dry up vital British commercial relations with the continent. To ensure the effectiveness of the Continental System, he sought to force Portugal, a traditional British trading partner, to observe it; when diplomatic means failed in 1808, Napoleon had the country occupied, forcing the ruling dynasty of Braganza to flee the country and seek refuge in its main colony, Brazil. In a move that would prove to be both uninspired and ill-handled, Napoleon also overstepped his power and decided to change the ruling dynasty of Spain, replacing King Charles IV with his own brother, Joseph, who became King José I of Spain. The new king was, however, not well received by the population and much of the country's ruling elite who felt that Napoleon was imposing on them, which triggered a bloody guerrilla war throughout the country. The French position in the peninsula was rendered untenable after the Battle of Bailen, a rare and resounding defeat for the French forces and an event that greatly encouraged the Austrian war party. With Napoleon forced to intervene personally and commit increasingly significant forces to the Spanish, the French military position in central Europe was severely weakened. In addition, Franco-Russian relations had deteriorated and, although the two countries remained allies on paper, it was unlikely that Russia would commit itself seriously to fighting France's enemies on the continent.
France's main adversary in central Europe was the Austrian Empire. Defeated at Ulm and Austerlitz in 1805 and forced to conclude the humiliating Peace of Pressburg, Austria still possessed a formidable army which, in the years following Austerlitz, had undergone major reforms. By 1809, the state was almost bankrupt and acutely aware that it could not retain its status as a great power if it did not manage to regain some of its former influence in Germany and Italy. Encouraged by Napoleon's peninsular imbroglio, British subsidies and the promise of a military intervention in northern Europe, the Austrians decided that the European political context of 1808 and 1809 offered their best chance to retake lost provinces. In order to win the war against the French, Vienna was counting on massive nationalist, anti-French uprisings throughout Germany and hoping that an early success might convince Prussia to join the new coalition, while calculating that Russia would most likely not interfere in support of the French. Austrian military preparations were accelerated in 1808 and early 1809, with operations set to occur in several war theatres, including the main one in Bavaria and sideshows in Italy, Dalmatia, Westphalia, Tyrol and Poland. In stark contrast to 1805, by 1809 Austria had managed to reform its military and build a relatively modern and overall redoubtable army, placed in the hands of their best commander, Archduke Charles of Austria, brother of Emperor Francis I of Austria.