one of the most celebrated naval engagements in European history. It was fought on Oct. 21, 1805, off Cape Trafalgar on the southern coast of Spain, pitting a British fleet of 27 ships under the command of Adm. Horatio Nelson against a slightly larger combined fleet of France and Spain, commanded by Vice Adm. Pierre Charles de Villeneuve (1763–1806) of France.

The French admiral was under orders from Napoleon to slip out of Cádiz, Spain, which was under British blockade, to land troops in southern Italy, where the French were fighting. Leaving port on October 19–20, he was intercepted by Nelson on the morning of October 21. Villeneuve formed his fleet into a single battle line, south to north. Nelson, however, surprised his adversary by the bold strategy of ordering his ships into two groups, each of which assaulted and cut through the French fleet at right angles, demolishing the battle line; this created confusion that gave the British an advantage. The battle began shortly before noon; when it ended, in the late afternoon, some 20 French and Spanish ships had been destroyed or captured, while not a single British vessel was lost. Villeneuve himself was taken prisoner, along with thousands of his sailors. The British suffered about 1500 casualties, among them Lord Nelson, who was mortally wounded. The overwhelming British victory forever wrecked Napoleon's plan of invading England and gave the British unquestioned supremacy at sea for the rest of the century.