Historians estimate that between 10 and 18 million Africans were enslaved by Arab slave traders and taken across the Red Sea, Indian Ocean, and Sahara desert between 650 and 1900.[2][3][4][5] It should be noted that the term Arab when used in historical documents often represented a cultural term rather than a "racial" term, and many of the "Arab" slave traders such as Tippu Tip and others were indistinguishable from the "Africans" whom they enslaved and sold. Due to the nature of the Arab slave trade it is also impossible to be precise about actual numbers.[6][7][8][9]
Periodic Arab raiding expeditions were sent from Islamic Iberia to ravage the Christian Iberian kingdoms, bringing back booty and slaves. In a raid against Lisbon in 1189, for example, the Almohad caliph Yaqub al-Mansur took 3,000 female and child captives, while his governor of Córdoba, in a subsequent attack upon Silves in 1191, took 3,000 Christian slaves.[10]
Arabs also enslaved substantial numbers of Europeans. According to Robert Davis between 1 million and 1.25 million Europeans were captured by Barbary corsairs, who were vassals of the Ottoman Empire, and sold as slaves between the 16th and 19th centuries.[11][12] These slaves were captured mainly from seaside villages from Italy, Spain, Portugal and also from more distant places like France or England, the Netherlands, Ireland and even Iceland. The impact of these attacks was devastating – France, England, and Spain each lost thousands of ships, and long stretches of the Spanish and Italian coasts were almost completely abandoned by their inhabitants. Pirate raids discouraged settlement along the coast until the 19th century.[13][14]