Corsair, pirate or privateer, particularly those rovers who from the beginning of the 16th century through the first third of the 19th century cruised from such Barbary ports as Algiers, Tripoli, and Tunis in North Africa. They preyed upon shipping in the Mediterranean Sea and in the Atlantic Ocean, ravaging the coasts and seizing ships as far north as the British Isles and even Iceland. The immediate cause of the development of corsair states and fleets at the beginning of the 16th century was the final Christian defeat of the Muslims in Spain in 1492. The Muslims then fled to the northern coast of Africa, where they founded autonomous states or provinces as divisions of the Ottoman Empire. The Muslim rulers of the Barbary Coast were supported chiefly by the booty and slaves captured in pirate raids. The raids, which began as retaliation against Spain, expanded into piracy against the ships of all nations. Many attempts were made to put a stop to piracy in the Mediterranean, including the U.S. naval action against Tripoli between 1801 and 1805 and a U.S. expedition against Algiers in 1815 under the American naval commander Stephen Decatur. His expedition was the first serious attempt to put an end to the long-established power of the corsairs. It was followed by the successful bombardment of Algiers in 1816 by Edward Pellew, 1st viscount Exmouth. The corsairs were not totally suppressed, however, until the French occupied Algiers in 1830.

See also Barbary Coast; Tripolitan War.