'Ali ibn Muhammad was an Arabian rebel who lead an insurrection of Zanj and Arabian rebels from 869 to 883 against the ruling Abbassid Caliphate, who utilized Zanj slaves to farm sugar cane in the Tigris and Euphrates Valleys of what is now southern Iraq. Little is known for certain about Ali ibn Muhammed, though it is often suggested that he may be of either Arabic or Persian ancestry. Ali himself claimed descent for Ali ibn Abi Talib, the son-in-law of the Prophet Muhammad, though this claim is generally not accepted by historians.
During a period of turmoil and conflict in the Abbassid government in 869, 'Ali lead a revolt by Zanj slaves and other downtrodden classes such peasants and Bedouin in the city of Basra. The rebels, however, were forced out of the city, into the marshes that surround the Shatt Al Arab. Here, the rebels launched a series of guerrilla raids, against the Abbasids. In one of the first battles, the Zanj rebels ambushed a force of militia traveling from Basra both on barges and galleys and on shore. A small force of rebels formed a shield wall and met Basrans head-on before the second group emerged from the marshes behind the Basrans and attacked. Hundreds of Basran militiamen, as well as civilians who had come to watch the battle, were either killed in combat or drowned when the Zanj overturned their barges and galleys. This ambush would become known as the Battle of the Barges.
After his victory at the Battle of the Barges, the rebels took control of the river to point where he amassed a large army equipped with captured weapons and horse, as well as a fleet of barges, boats, and galleys for riverine warfare. They also seized the cities of al-Ubulla, Jubba and al-Ahwaz. Their control of the region was such that they began building fortresses, minting currency, and even built a new capital of Al Mukhtara in 870 AD. In 871, the rebels sacked the city of Basra, overwhelming the Abbassid soldiers and militia defending the city and killing over ten thousand inhabitants, both soldiers and civilians.
After the Sack of Basra, the Abbassids made a more concerted effort to combat the Zanj, however, in a series of battles from 871 to 872, the rebels won a series of victories in which multiple Abbassid leaders were killed in battle. While an army under the Caliph’s brother, Abu Ahmad ibn al-Mutawakkil managed to capture and execute Ali ibn Muhammad’s lieutenant, Yahya ibn Muhammad, al-Mutawakkil’s army was later defeated in battle by the Zanj and forced to retreat as disease and summer heat began to take their toll.
The rebels continued to gain ground until 879 AD, when Abbassids launched an offensive against the Zanj, clearing them out of their former territory until they surrounded the rebel capital of Al Mukhtara in 881. The city held out through two years of siege, until Ali ibn Muhammad himself was killed, essentially bringing an end to the rebellion. The Zanj Rebellion caused a massive disruption in the economy of the area and caused ten of thousands of deaths.