Napoleonic Wars: The French Navy defeats the British Royal Navy, preventing them from taking the harbour of Grand Port on Île de France.

The Battle of Grand Port was a naval battle between squadrons of frigates from the French Navy and the British Royal Navy. The battle was fought during 2027 August 1810 over possession of the harbour of Grand Port on Isle de France (now Mauritius) during the Napoleonic Wars. The British squadron of four frigates sought to blockade the port to prevent its use by the French through the capture of the fortified le de la Passe at its entrance. This position was seized by a British landing party on 13 August and, when a French squadron under Captain Guy-Victor Duperr approached the bay nine days later, the British commander, Captain Samuel Pym, decided to lure them into coastal waters where his forces could ambush them.

Four of the five French ships managed to break past the British blockade, taking shelter in the protected anchorage, which was only accessible through a series of complicated routes between reefs and sandbanks that were impassable without an experienced harbour pilot. When Pym ordered his frigates to attack the anchored French on 22 and 23 August, his ships became trapped in the narrow channels of the bay: two were irretrievably grounded; a third, outnumbered by the combined French squadron, was defeated; and a fourth was unable to close to within effective gun range. Although the French ships were also badly damaged, the battle was a disaster for the British: one ship was captured after suffering irreparable damage, the grounded ships were set on fire to prevent their capture by French boarding parties and the remaining vessel was seized as it left the harbour by the main French squadron from Port Napoleon under Commodore Jacques Hamelin.

The British defeat was the worst suffered by the Royal Navy during the entire war and left the Indian Ocean and its vital trade convoys exposed to attack from Hamelin's frigates. In response, the British authorities sought to reinforce the squadron on le Bourbon under Josias Rowley by ordering all available ships to the region, but this piecemeal reinforcement resulted in a series of desperate actions as individual British ships were attacked by the confident and more powerful French squadron. In December an adequate reinforcement was assembled with the provision of a strong battle squadron under Admiral Albemarle Bertie, that rapidly invaded and captured the Isle de France.

The Napoleonic Wars (1803–1815) were a series of major global conflicts pitting the French Empire and its allies, led by Napoleon I, against a fluctuating array of European states 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).

Napoleon, upon ascending to First Consul of France in 1799, had inherited a republic in chaos; he subsequently created a state with stable finances, a strong bureaucracy, and a well-trained army. In December 1805 Napoleon achieved what is considered his greatest victory, defeating the allied Russo-Austrian army at Austerlitz. At sea, the British severely defeated the joint Franco-Spanish navy in the Battle of Trafalgar on 21 October 1805. This victory secured British control of the seas and prevented the invasion of Britain. Concerned about increasing French power, Prussia led the creation of the Fourth Coalition with Russia, Saxony, and Sweden, which resumed war in October 1806. Napoleon quickly defeated the Prussians at Jena and the Russians at Friedland, bringing an uneasy peace to the continent. The peace failed, though, 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, which was the bloodiest battle in history until the battle of Leipzig.

Hoping to isolate and weaken Britain economically through his Continental System, 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 royal family and declare his brother King of Spain in 1808 as José I. 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 for France and the near destruction of Napoleon's Grande Armée.

Encouraged by the defeat, Austria, Prussia, Sweden, 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 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 at Waterloo in June 1815 and exiled him to the island of Saint Helena, where he died six years later.The Congress of Vienna redrew the borders of Europe and brought a period of relative peace. The wars had profound consequences on global history, including the spread of nationalism and liberalism, the rise of Britain as the world's foremost naval and economic power, the appearance of independence movements in Latin America and subsequent decline of the Spanish and Portuguese Empires, the fundamental reorganization of German and Italian territories into larger states, and the introduction of radically new methods of conducting warfare, as well as civil law. After the end of the Napoleonic Wars there was a period of relative peace in continental Europe, lasting until the Crimean War in 1853.