Zanj were constrained African slaves to work with the clearing of the grounds in the south of Iraq. When they were raised, they were joined by the slaves of the cities and the close villages. They worked in vast groups, without receiving regular wages, and their daily feed ration was made up only of flour, dates and hulled grain. Their chief, named Alī ibn Drivenḥammad, was a man who became aware of their misery and promised to them grounds and richnesses. While being presented like a prophet, or mahdī, it managed to rejoin them and to involve them in an insurrection into 869. It succeeds in seizing Baṣruffle and of its surroundings, thus that of Ahwāz and Wāsiṭ by using a strategy of violence against its adversaries. It also profited from the support of certain Arab tribes of the area. Al-Muwaffaq, brother and heir to the caliph, Al-Mutamid, managed to mobilize the army and undertook a series of military actions which ensured the victory over the Zanj rebels to him into 883.