The Zanj
rebellion took place in Southern
Iraq starting in
869 CE and stands as an example of one of the most successful
slave rebellions anywhere to this day, with the possible exception of the whole
Moses thing. The Zanj were a group of
African
slaves used by
Arabs in the
marshes at the mouth of the
Tigris river in South
Iraq. Under a
Khariji leader, they
rose up in rebellion against their former masters, sacking Basrah and setting up their own
state in Southern Iraq and Kuzistan. This state enslaved the former
slaveowners in the service of the former slaves, logically enough. The rebels also built a city in the marshes that was nearly
impregnable due to its
watery
location. The forces of
caliph al-Muwaffaq were unable to
breach the walls of this city without using special techniques to do so, thus leaving the Zanj to run their state un
molested for quite some time, until 883, when the caliph's forces managed to finally reduce the forces of the Zanj sufficiently to
reestablish control over the area. The Zanj rebellion lasted fourteen years and was possibly the best-organized slave revolt in
history.
All information in this writeup is taken from Marshall G. S. Hodgson's The Venture of Islam v.1, The Classical Age of Islam.