Zanzibar and its ports served as a major center for the slave market between Africa and Asia, particularly the Middle East. Slave traders would bargain with local chiefs exchanging guns, beads and cloth for ivory and humans. Militarized tribes would sometimes raid other tribes and sell their prisoners as slaves. Convicted criminals were also sold as slaves, and often their penalties included enslaving their families.
Visiting some of the historic sites of the slave trade is a sobering way to remember this dark period of our relatively recent history.