information:extraction
Arab traders and markets

The enslavement of Africans for eastern markets started before the 7th century but remained at low levels until 1750. The volume of the trade peaked around 1850 but may largely have ended around 1900. Muslim participation in the slave trade started in the eighth and ninth centuries AD, beginning with small-scale movements of people, largely from the eastern Great Lakes region and the Sahel. Islamic law allowed slavery, but prohibited slavery involving other pre-existing Muslims; as a result, the main targets for enslavement were the people who lived in the frontier areas of Islam in Africa.

The trade of slaves across the Sahara and the Indian Ocean also has a long history beginning with the control of sea routes by Arab traders in the ninth century. It is estimated that, at that time, a few thousand enslaved people were taken each year from the Red Sea and Indian Ocean coast. They were sold throughout the Middle East. This trade accelerated as superior ships led to more trade and greater demand for labour on plantation. Eventually, tens of thousands per year were being taken. On the Swahili Coast, the Afro-Arab slavers captured Bantu peoples from the interior and brought them to the littoral. There, the slaves gradually assimilated in the rural areas, particularly on the Unguja and Pemba islands.

This changed the slave relationships by creating new forms of employment by slaves (as eunuchs to guard harems, and in military units) and creating conditions for freedom (namely conversion —although it would only free a slave's children). Although the level of trade remained relatively small, the total number of slaves over the multiple centuries of the trade's existence. Because of its small and gradual nature, the impact on slavery practices in communities that did not convert to Islam was relatively small. However, in the 1800s, the slave trade from Africa to the Islamic countries picked up significantly. When the European slave trade ended around the 1850s, the slave trade to the east picked up significantly only to end with the European colonization of Africa around 1900. Between 1500 and 1900, up to 17 million Africans slaves were transported by Muslim traders to the coast of the Indian Ocean, the Middle East, and North Africa.

In 1814, Swiss explorer Johann Burckhardt wrote of his travels in Egypt and Nubia, where he saw the practice of slave trading: "I frequently witnessed scenes of the most shameless indecency, which the traders, who were the principal actors, only laughed at. I may venture to state, that very few female slaves who have passed their tenth year, reach Egypt or Arabia in a state of virginity."

David Livingstone talking about the slave trade in East Africa in his journals:

To overdraw its evil is a simple impossibility.

Livingstone wrote about a group of slaves forced by Arab slave traders to march in the African Great Lakes region when he was travelling there in 1866:

19th June 1866 – We passed a woman tied by the neck to a tree and dead, the people of the country explained that she had been unable to keep up with the other slaves in a gang, and her master had determined that she should not become anyone's property if she recovered. 26th June 1866 –... We passed a slave woman shot or stabbed through the body and lying on the path: a group of men stood about a hundred yards off on one side, and another of the women on the other side, looking on; they said an Arab who passed early that morning had done it in anger at losing the price he had given for her, because she was unable to walk any longer. 27th June 1866 – To-day we came upon a man dead from starvation, as he was very thin. One of our men wandered and found many slaves with slave-sticks on, abandoned by their masters from want of food; they were too weak to be able to speak or say where they had come from; some were quite young.

The lethality of the trans-Saharan routes is comparable to those of the trans-Atlantic. Deaths of slaves in Egypt and North Africa were very high, even if they were fed and treated well. Medieval manuals for slave buyers – written in Arabic, Persian and Turkish – explained that Africans from Sudanic and Ethiopian areas are prone to illness and death in their new environments.

Zanzibar was once East Africa's main slave-trading port, and under Omani Arabs in the 19th century as many as 50,000 slaves were passing through the city each year via the Zanzibar slave trade.