The Battle of Waterloo, 18 June 1815, where Napoleon suffered his final defeat at the hands of Arthur Wellesley, the 1st Duke of Wellington, which marked the formal end of the Napoleonic Wars and the final collapse of the First French Empire.
All in all, French armies wrought much suffering in Europe, but they also radically changed the lay of the land. In much of Europe, gone were feudal relations; the power of the guilds; the absolutist control of monarchs and princes; the grip of the clergy on economic, social, and political power; and the foundation of the Ancien Régime, which treated different people unequally based on their birth status. These changes created the type of inclusive economic institutions that would then allow industrialization to take root in these places. By the middle of the nineteenth century, industrialization was rapidly under way in almost all the places that the French controlled, whereas places such as Austria-Hungary and Russia, which the French did not conquer, or Poland and Spain, where French hold was temporary and limited, were still largely stagnant.
~ J. Christopher Herold, The Age of Napoleon

The Napoleonic Wars (1803–1815) were a series of major conflicts which pitted the First French Empire and its allies, led by Napoleon I, against a fluctuating array of European powers formed into various coalitions. It produced a period of French domination over most of continental Europe. 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 (1813–14), and the Seventh (1815), which lasted 100 days.

Napoleon, upon his ascension to First Consul of France in 1799 following his bloodless coup of 9-10 November, inherited a republic in chaos; Subsequently, he created a state with stable finances, a strong bureaucracy, and a well-trained army. In 1805, Austria and Russia formed 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 21 October 1805. This victory secured British domination of the seas and thereby prevented the invasion of Britain itself. Concerned about France's increasing power and influence, Prussia led the creation of the Fourth Coalition with Russia, Saxony, and Sweden, and war resumed in October 1806. Napoleon, however, quickly defeated the Prussians at Jena and the Russians at Friedland, bringing an uneasy peace to the continent. The peace failed, however, as war broke out in 1809, with the badly prepared Fifth Coalition, led by Austria. At first, the Austrians won a stunning victory at Aspern-Essling, but were quickly defeated at Wagram.

Hoping to isolate and weaken Britain economically through his Continental System, Napoleon launched an invasion of Portugal, which was 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 royal family and declare his brother King of Spain in 1808 as José I. This was a major mistake, however, as the Spanish and Portuguese revolted with British support and expelled the French from Iberia in 1814 after six years of fighting.

Concurrently, Russia, unwilling to bear the economic consequences of reduced trade, routinely violated the Continental System, prompting Napoleon to launch a massive invasion of Russia in 1812. The resulting campaign ended in disaster and the near destruction of Napoleon's Grande Armée. This occurred around the same time that the United States of America was fighting the War of 1812 against the British.

Encouraged by Napoleon's disastrous defeat at the hands of Russia, the countries of Austria, Prussia, Sweden, and Russia itself 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 into southwestern France. Coalition troops captured Paris at the end of March 1814 and forced Napoleon to abdicate in April. He was exiled to the island of Elba, and the Bourbons were restored to power. But Napoleon escaped in February 1815, and reassumed control of France for around one hundred days. After forming the Seventh Coalition, the Allies defeated him once more, this time for good, at Waterloo in June 1815. He abdicated in favor of his son Napoleon II. However Napoleon II was not recognized as Emperor, with Louis XVIII soon after being put back on the throne, and after attempting a futile escape to the United States of America, he surrendered to the British, who thereafter exiled him to Saint Helena, where he died six years later, unable to escape again, of Stomach Cancer. The Bourbons were later overthrown again in the July Revolution, in 1830.