Archduke Charles, Duke of Teschen in the context of "Duchy of Teschen"

The War of the Fifth Coalition was a European conflict in 1809 that was part of the Napoleonic Wars and the Coalition Wars. The main conflict took place in Central Europe between the Austrian Empire of Francis I and Napoleon's French Empire. The French were supported by their client states—the Kingdom of Italy, the Confederation of the Rhine and the Duchy of Warsaw. Austria was supported by the Fifth Coalition which included the United Kingdom, Portugal, Spain, and the Kingdoms of Sardinia and Sicily, although the latter two took no part in the fighting. By the start of 1809 much of the French army was committed to the Peninsular War against Britain, Spain and Portugal. After France withdrew 108,000 soldiers from Germany, Austria attacked France to seek the recovery of territories lost in the 1803–1806 War of the Third Coalition. The Austrians hoped Prussia would support them, having recently been defeated by France, but Prussia chose to remain neutral.

On 10 April 1809, Austrian forces under Archduke Charles crossed the border of Bavaria, a French client state. The French response, under Louis-Alexandre Berthier, was disorganised but order was imposed with the arrival of Napoleon on 17 April. Napoleon led an advance to Landshut, hoping to cut off the Austrian line of retreat and sweep into their rear. Charles crossed the Danube at Regensburg, which allowed him to retreat eastwards, although he failed to reach the Austrian capital, Vienna, before the French. A French assault across the Danube was repulsed on 21–22 May at the Battle of Aspern-Essling but a repeat attack was successful in July. Napoleon won a major victory at the 5–6 July Battle of Wagram, which forced the Austrians to sign the Armistice of Znaim on 12 July. Austrian invasions of the Duchy of Warsaw and Saxony (where they fought alongside the Black Brunswickers) were repulsed and they were driven out of their territories in Italy. British forces landed in Walcheren, in the French client state of Holland, but were unable to seize their objective of capturing Antwerp and later withdrew.

Austrian nationalism (Austrian German: Österreichischer Nationalismus) is the nationalism that asserts that Austrians are a nation and promotes the cultural unity of Austrians. Austrian nationalism originally developed as a cultural nationalism that emphasized a Catholic religious identity. This in turn led to its opposition to unification with Protestant-majority Prussia, something that was perceived as a potential threat to the Catholic core of Austrian national identity. It was also used to protect the rule of the Habsburgs.

Austrian nationalism first arose during the Napoleonic Wars, with Joseph von Hormayr as a prominent Austrian nationalist political leader at the time. In the 1930s the Fatherland Front government of Engelbert Dollfuss and Kurt Schuschnigg rejected current pan-German aspirations to join Austria with a Protestant-dominated Germany, whilst not wholly rejecting a potential union and claiming that any unification of Austria with Germany would require a federal German state where Austria and Austrians were guaranteed privileged status recognizing an Austrian nation within a German Kulturnation. Following the events of World War II and Nazism, Austrians began to reject the German identity, and a broader Austrian identity replaced it. After the war, some Austrians went as far as describing themselves as "Hitler's first victim".

In the Battle of Aspern-Essling (21–22 May 1809), Napoleon crossed the Danube near Vienna, but the French and their allies were attacked and forced back across the river by the Austrians under Archduke Charles. It was the first time Napoleon had been personally defeated in a major battle, as well as his first battle defeat in 10 years since the siege of Acre, and his first battle defeat as head of state, although he did suffer a tactical defeat in the Battle of Caldiero and in the Second Battle of Bassano. Archduke Charles drove out the French but fell short of destroying their army. The French lost over 20,000 men, including one of Napoleon's ablest field commanders and closest friends, Marshal Jean Lannes.

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.