The Zanj Rebellion was a major revolt against the Abbasid Caliphate, which took place from 869 until 883. Begun near the city of Basra in present-day southern Iraq and led by one Ali ibn Muhammad, the insurrection involved both enslaved and freed Africans exported in the Indian Ocean slave trade and transported to slavery in the Abbasid Caliphate in the Middle East, principally to drain the region's salt marshes. It grew to involve slaves and freemen, including both Eastern Africans and Arabs, from several regions of the Caliphate, and claimed tens of thousands of lives before it was fully defeated.