A corsair was a private individual who commanded an armed vessel and sailed the seas against the enemy of his country and his faith at his own risk and profit, covered by letters-patent issued by his government. There was a legal distinction between a corsair and a pirate. In theory, the former acted within the limits of the law; the latter outside it. In everyday practice there was hardly any difference in their performance. Nor was there any dissimilarity between Muslim and Christian corsairs. Both sought the same prey: the commercial trading vessel, flying any flag, friend or foe. Prizes were made by both: at sea by seizing other vessels, on land by raiding coastal towns and villages. Such were the Barbary corsairs. Their states, as their name suggests, lay in the Barbary region on the North African coast.
Algiers (mod. Alger, Algeria), Tripoli (mod. Tarābulus, Libya), and Tunis were the leading Barbary Regencies. They owe their origin to two closely related factors. First, there was the corsairs’ reaction to Spain’s systematic conquest of strategic points on the North African coast: Melilla (1497), Mers el-Kebir (1505), Oran (1509), Algiers, Bejaïa (Bougie), and Tripoli (1510). Second, there was the same corsairs’ resort to the increasingly powerful Ottoman sultan at Constantinople for aid and protection in their war against imperial Spain. In return they recognized him as their religious and political leader, from whose expanding empire they were now allowed to recruit armies that helped maintain internal political stability in the Barbary States and defended them from foreign invasion. They also made their wide corsairing activity possible.
The Barbary corsairs succeeded in conquering and exploiting the fertile hinterlands of the cities of Algiers, Tripoli, and Tunis, upon which they built strong military states, a prosperous economy, and a flourishing trade in agricultural products. The latter were exchanged for manufactured goods (such as war matériel and shipbuilding) from friends and foes alike in Christian Europe. Each state (with Algiers leading the way) soon developed into a semi- autonomous Muslim base, from which the Barbary corsairs operated in the endless holy war between Islam and Christianity. The corsairs also had long-term effects on the Christian Mediterranean. Their widespread activities necessitated sounder defenses on both land and sea on the part of Christian governments. On land they dictated the building of coastal towers, massive walls, and other structures; on sea merchant fleets became more strongly armed and preferred to sail in convoy. But the Barbary corsairs also encouraged Christian states (such as the Papal States, Livorno, and Hospitaller Malta) to send their own navies to seek them out and capture them. The slave trade flourished.
The history of the Barbary corsairs is generally divided into three distinct phases. The first is known as the grand heroic phase (1520s-1580), the period of their participation alongside the Turkish armada in the Ottoman Empire’s struggle against Spain and its allies for mastery of the Mediterranean. Charles V’s full-scale Spanish crusade against Tunis (1535), his disaster at Algiers (1541), the Ottoman reconquest of Tripoli from the Hospitallers (1551), the long unsuccessful Muslim siege of Malta (1565), and the battle of Lepanto (1571) were successive stages punctuating this crusading phase. The second is known as the mercantile phase (1580-c. 1650). By now, corsair activity had been allowed to develop into an economic jihād (holy war) an important industry with the pursuit of gain as its main driving force. Galley fleets sailed out to raid Christian commerce. Spain’s shipping and that of its European colonies (such as Naples, Sardinia, and Sicily) were potential targets, and so was the shipping of Hospitaller Malta and of states at formal war with the Ottoman Empire. England, France, and Holland were generally not among the corsairs’ enemies. This in part reflected these trading nations’ greater military and naval capacity, which could impose truces and peace treaties on the Barbary corsair states at will; in part, it depended on their often changing perceptions of the “Turk.” About one-seventh of the value of the booty (human and material) made by the Barbary corsairs was assigned, in harmony with precepts in the Qur’ân, to the state that had covered the corsairs with letters-patent. Other fixed proportions went to port officials and brokers, and to finance the upkeep of the harbor. The rest was shared equally between the ship owners and the crew. The third phase, known as the declining phase, was marked by the increasing, almost exclusive, participation of the state. The activity of the Barbary corsairs was brought to an end in 1830 with the French conquest of Algiers.