Scope of the trade
A 19th-century European engraving of Arab slave-trading caravan transporting African slaves across the Sahara
The Arab slave trade, across the Sahara desert and across the Indian Ocean, began after Muslim Arab and Swahili traders won control of the Swahili Coast and sea routes during the 9th century (see Sultanate of Zanzibar). These traders captured Bantu peoples (Zanj) from the interior in present-day Kenya, Mozambique and Tanzania and brought them to the coast. There, the slaves gradually assimilated in the rural areas, particularly on the Unguja and Pemba islands.
Some historians assert that as many as 17 million people were sold into slavery on the coast of the Indian Ocean, the Middle East, and North Africa, and approximately 5 million African slaves were bought by Muslim slave traders and taken from Africa across the Red Sea, Indian Ocean, and Sahara desert between 1500 and 1900.
The captives were sold throughout the Middle East. This trade accelerated as superior ships led to more trade and greater demand for labour on plantations in the region. Eventually, tens of thousands of captives were being taken every year.
The Indian Ocean slave trade was multi-directional and changed over time. To meet the demand for menial labor, Bantu slaves bought by Arab slave traders from southeastern Africa were sold in cumulatively large numbers over the centuries to customers in Egypt, Arabia, the Persian Gulf, India, European colonies in the Far East, the Indian Ocean islands, Ethiopia and Somalia.
Slave labor in East Africa was drawn from the Zanj, Bantu peoples that lived along the East African coast. The Zanj were for centuries shipped as slaves by Arab traders to all the countries bordering the Indian Ocean. The Umayyad and Abbasid caliphs recruited many Zanj slaves as soldiers and, as early as 696, there were slave revolts of the Zanj against their Arab enslavers in Iraq (see Zanj Rebellion). Ancient Chinese texts also mention ambassadors from Java presenting the Chinese emperor with two Seng Chi (Zanj) slaves as gifts, and Seng Chi slaves reaching China from the Hindu kingdom of Srivijaya in Java.
The Zanj Rebellion, a series of uprisings that took place between 869 and 883 AD near the city of Basra (also known as Basara), situated in present-day Iraq, is believed to have involved enslaved Zanj that had originally been captured from the African Great Lakes region and areas further south in East Africa. It grew to involve over 500,000 slaves and free men who were imported from across the Muslim empire and claimed over "tens of thousands of lives in lower Iraq".
The Zanj who were taken as slaves to the Middle East were often used in strenuous agricultural work. As the plantation economy boomed and the Arabs became richer, agriculture and other manual labor work was thought to be demeaning. The resulting labor shortage led to an increased slave market.
It is certain that large numbers of slaves were exported from eastern Africa; the best evidence for this is the magnitude of the Zanj revolt in Iraq in the 9th century, though not all of the slaves involved were Zanj. There is little evidence of what part of eastern Africa the Zanj came from, for the name is here evidently used in its general sense, rather than to designate the particular stretch of the coast, from about 3°N. to 5°S., to which the name was also applied.
The Zanj were needed to take care of:
the Tigris-Euphrates delta, which had become abandoned marshland as a result of peasant migration and repeated flooding, could be reclaimed through intensive labor. Wealthy proprietors "had received extensive grants of tidal land on the condition that they would make it arable." Sugar cane was prominent among the products of their plantations, particularly in Khūzestān Province. Zanj also worked the salt mines of Mesopotamia, especially around Basra.
Their jobs were to clear away the nitrous topsoil that made the land arable. The working conditions were also considered to be extremely harsh and miserable. Many other people were imported into the region, besides Zanj.
Historian M. A. Shaban has argued that rebellion was not a slave revolt, but a revolt of blacks (zanj). In his opinion, although a few runaway slaves did join the revolt, the majority of the participants were Arabs and free Zanj. If the revolt had been led by slaves, they would have lacked the necessary resources to combat the Abbasid government for as long as they did.
Walter Rodney argues that the term Arab Slave Trade is a historical misnomer since bilateral trade agreements between a myriad of ethnic groups across the proposed 'Zanj trade network' characterized much of the acquisition process of chattel, and more often than not indentured servants.
Muslims also enslaved Europeans. According to Robert Davis, between 1 million and 1.25 million Europeans were captured between the 16th and 19th centuries by Barbary corsairs, who were vassals of the Ottoman Empire, and sold as slaves. 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. They were also taken from ships stopped by the pirates.
The effects of these attacks were devastating: France, England, and Spain each lost thousands of ships. Long stretches of the Spanish and Italian coasts were almost completely abandoned by their inhabitants, because of frequent pirate attacks. Pirate raids discouraged settlement along the coast until the 19th century.
Periodic Muslim raiding expeditions were sent from Islamic Iberia to ravage the Christian Iberian kingdoms, bringing back slaves. In a raid against Lisbon in 1189, for example, the Almohad Berber Muslim caliph, Abu Yusuf 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.
Patrick Manning writes that although the "Oriental" or "Arab" slave trade is sometimes called the "Islamic" slave trade, a religious imperative was not the driver of the slavery. He further argues such use of the terms "Islamic trade" or "Islamic world" erroneously treats Africa as being outside Islam, or a negligible portion of the Islamic world. According to European historians, propagators of Islam in Africa often revealed a cautious attitude towards proselytizing because of its effect in reducing the potential reservoir of slaves.
The subject merges with the Oriental slave trade, which followed two main routes in the Middle Ages:
The Arab slave trade originated before Islam and lasted more than a millennium. To meet the demand for plantation labor, these captured Zanj slaves were shipped to the Arabian peninsula and the Near East, among other areas.