History of Portugal (1777–1834) in the context of "War of the Second Coalition"

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.

In the War of the Sixth Coalition (French: Guerre de la Sixième Coalition; December 1812 – May 1814), sometimes known in Germany as the Wars of Liberation (German: Befreiungskriege), a coalition of Austria, Prussia, Russia, Spain, the United Kingdom, Portugal, Sweden, Sardinia, and a number of German States defeated France and drove Napoleon into exile on Elba. After the disastrous French invasion of Russia of 1812 in which they had been forced to support France, Prussia and Austria joined Russia, the United Kingdom, Sweden, and Portugal, and the rebels in Spain who were already at war with France. The invasion of Russia cost the French many seasoned soldiers, so Napoleon took action to engage "Marie-Louises", young conscripts who were barely familiar with military affairs; they were called up from October 1813 to 1815. However, the constant warfare weakened the Coalition nations as well. The Russian military was particularly depleted after 1812, and Prussia also suffered a significant downgrade as a result of its losses in 1806–1807; nevertheless, it carried out large-scale reforms to improve the situation in the Prussian Army. Later, having encountered the Prussians in the Battle of Lützen, Napoleon would say: "These animals have learned something."

The War of the Sixth Coalition saw battles at Lützen, Bautzen, and Dresden. The even larger Battle of Leipzig (also known as the Battle of Nations) was the largest battle in European history before World War I. Ultimately, Napoleon's earlier setbacks in Spain, Portugal and Russia proved to be the seeds of his undoing. With their armies reorganized, the allies drove Napoleon out of Germany in 1813 and invaded France in 1814. The Allies defeated the remaining French armies, occupied Paris, and forced Napoleon to abdicate and go into exile. The French monarchy was revived by the allies, who handed rule to the heir of the House of Bourbon in the Bourbon Restoration.