Trafalgar, Battle of, October 21, 1805, a naval victory of Admiral Horatio Nelson's British fleet over Napoleon's fleet. In this battle the British destroyed Napoleon's sea power and eliminated any possibility of an invasion of England.

The battle was fought off Cape Trafalgar, between Cádiz and Gibraltar, on the southern coast of Spain. Knowing that without sea power Napoleon could not launch an attack on England, Nelson had spent the summer pursuing the enemy fleet. French Vice Admiral Villeneuve, with 33 French and Spanish ships under his command, had taken refuge in the harbor of Cádiz. When, on Napoleon's order, he sailed out, he was attacked by Nelson's 27 ships. Nelson's tactics, which by a feint kept the first ships of the enemy line out of the action while he and Vice Admiral Cuthbert Collingwood attacked the center and rear, were brilliantly successful. Only 15 French and Spanish ships escaped, and 6 of these were later captured or wrecked. Nelson was killed in the action.