The Napoleonic Wars (1803–1815) were a series of major conflicts pitting the French Empire and its allies, led by Napoleon I, against a fluctuating array of European powers formed into various coalitions, financed and usually led by the United Kingdom. The wars stemmed from the unresolved disputes associated with the French Revolution and its resultant conflict. The wars are often categorised into five conflicts, each termed after the coalition that fought Napoleon: the Third Coalition (1805), the Fourth (1806–07), the Fifth (1809), the Sixth (1813), and the Seventh (1815).
Napoleon, upon ascending to First Consul of France in 1799, had inherited a chaotic republic; he subsequently created a state with stable finances, a strong bureaucracy, and a well-trained army. In 1805, Austria and Russia started the Third Coalition and waged war against France. In response, Napoleon defeated the allied Russo-Austrian army at Austerlitz in December 1805, which is considered his greatest victory. At sea, the British severely defeated the joint Franco-Spanish navy in the Battle of Trafalgar on October 1805. This victory secured British control of the seas and prevented the invasion of Britain itself. Concerned about the increasing French power, Prussia led the creation of the Fourth Coalition with Russia, Saxony and Sweden, and the resumption of war in October 1806. Napoleon quickly defeated the Prussians in Jena and the Russians in Friedland, bringing an uneasy peace to the continent. The peace failed, though, as war broke out in 1809, when the badly prepared Fifth Coalition, led by Austria, was quickly defeated in Wagram.
Hoping to isolate Britain economically, Napoleon launched an invasion of Portugal, the only remaining British ally in continental Europe. After occupying Lisbon in November 1807, and with the bulk of French troops present in Spain, Napoleon seized the opportunity to turn against his former ally, depose the reigning Spanish Bourbon family and declare his brother King of Spain in 1808 as Joseph I. The Spanish and Portuguese revolted with British support, and, after six years of fighting, expelled the French from Iberia in 1814.
Concurrently, Russia, unwilling to bear economic consequences of reduced trade, routinely violated the Continental System, enticing Napoleon to launch a massive invasion of Russia in 1812. The resulting campaign ended with the dissolution and disastrous withdrawal of the French Grande Armée.
Encouraged by the defeat, Prussia, Austria, and Russia formed the Sixth Coalition and began a new campaign against France, decisively defeating Napoleon at Leipzig in October 1813 after several inconclusive engagements. The Allies then invaded France from the East, while the Peninsular War spilled over southwestern French territory. Coalition troops captured Paris at the end of March 1814 and forced Napoleon to abdicate in early April. He was exiled to the island of Elba, and the Bourbons were restored to power. However, Napoleon escaped in February 1815, and reassumed control of France. The Allies responded with the Seventh Coalition, defeating Napoleon permanently at Waterloo in June 1815 and exiling him to St Helena a British territory midway between Africa and Brazil, where he died six years later.
The Congress of Vienna redrew the borders of Europe, and brought a lasting peace to the continent. The wars had profound consequences on global history, including the spread of nationalism and liberalism, the rise of the British Empire as the world's foremost power, the appearance of independence movements in Latin America and subsequent collapse of the Spanish Empire, the fundamental reorganisation of German and Italian territories into larger states, and the establishment of radically new methods of conducting warfare.