HMS Bellerophon, known to sailors as the "Billy Ruffian", was a ship of the line of the Royal Navy. A third-rate of 74 guns, she was launched in 1786. Bellerophon served during the French Revolutionary and Napoleonic Wars, mostly on blockades or convoy escort duties. She fought in three fleet actions: the Glorious First of June (1794), the Battle of the Nile (1798) and the Battle of Trafalgar (1805). While the ship was on blockade duty in 1815, Napoleon boarded Bellerophon so he could surrender to the ship's captain, ending 22 years of almost continuous war between Britain and France.

Built at Frindsbury, near Rochester in Kent, Bellerophon was initially laid up in ordinary, briefly being commissioned during the Spanish and Russian Armaments. She entered service with the Channel Fleet on the outbreak of the French Revolutionary Wars in 1792, and took part in the Glorious First of June in 1794, the first major fleet action of the wars. Bellerophon narrowly escaped being captured by the French in 1795, when her squadron was nearly overrun by a more powerful French fleet at the First Battle of Groix, but the bold actions of the squadron's commander, Vice-Admiral Sir William Cornwallis, caused the French to retreat. She played a minor role in efforts to intercept a French invasion force bound for Ireland in 1797, and then joined the Mediterranean Fleet under Sir John Jervis. Detached to reinforce Rear-Admiral Sir Horatio Nelson's fleet in 1798, she took part in the decisive defeat of a French fleet at the Battle of the Nile, where she suffered severe damage and lost several officers while engaging the much larger French flagship Orient. She returned to England before being sent to the West Indies, where she spent the Peace of Amiens (180203) on cruises and convoy escort duty between the Caribbean and North America.

Bellerophon returned to European waters with the resumption of the wars with France, joining a fleet under Vice-Admiral Cuthbert Collingwood blockading Cadiz. The reinforced fleet, by then commanded by Horatio Nelson, engaged the combined Franco-Spanish fleet when it emerged from port. At the Battle of Trafalgar on 21 October Bellerophon fought a bitter engagement against Spanish and French ships, sustaining heavy casualties including the death of her captain, John Cooke. Following the battle, she escorted Nelson's body back to England. After repairs, Bellerophon was employed blockading the enemy fleets in the Channel and the North Sea. She plied the waters of the Baltic Sea in 1809, making attacks on Russian shipping, and by 1810 was off the French coast again, blockading their ports. She went out to North America as a convoy escort between 1813 and 1814, and in 1815 was assigned to blockade the French Atlantic port of Rochefort. In July 1815, defeated at Waterloo and finding escape to America barred by the blockading Bellerophon, Napoleon came aboard "the ship that had dogged his steps for twenty years" (according to maritime historian David Cordingly) to finally surrender to the British. It was Bellerophon's last seagoing service. She was paid off and converted to a prison ship in 1815, and was renamed Captivity in 1824 to free the name for another ship. Moved to Plymouth in 1826, she continued in service until 1834, when the last convicts left. The Admiralty ordered her to be sold in 1836; she was subsequently broken up for scrap.

Bellerophon's long and distinguished career has been recorded in literature and folk songs.

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.