The Zanj rebellion which occurred from 869 to 883 took place in Basra, which is modern-day Southern Iraq. It was led by Ali ibn Muhammed against the Abbasid Caliphate. The Zanj were captured from the coast of East Africa and brought to the area as slaves. The African slaves were captured so that they could tend to plantations and marshland that needed extensive work to be cultivable. In 869 amidst a brawl in Basra, Muhammed went to the city to inquire about the living and working conditions of the slaves.

Source: The North Africa Journal May 10, 2018 17:48 UTC