The Kharijites were an Islamic sect which emerged during the First Fitna (656–661). The first Kharijites were supporters of Ali who rebelled against his acceptance of arbitration talks to settle the conflict with his challenger, Mu'awiya, at the Battle of Siffin in 657. They asserted that "judgment belongs to God alone," which became their motto, and that rebels such as Mu'awiya had to be fought and overcome according to Qur'anic injunctions. Ali defeated the Kharijites at the Battle of Nahrawan in 658, but their insurrection continued. Ali was assassinated in 661 by a Kharijite dissident seeking revenge for the defeat at Nahrawan.
The Battle of Siffin as depicted in the 14th-century manuscript of the Tarikh-i Bal'ami
A 1909 photograph of the Nahrawan Canal
Arab-Sasanian dirham of the Azariqa leader Qatari ibn al-Fuja'a, struck circa 694–695, with the Kharijite slogan la hukma illa li-llah on the obverse margin
The First Fitna was the first civil war in the Islamic community. It led to the overthrow of the Rashidun Caliphate and the establishment of the Umayyad Caliphate. The civil war involved three main battles between the fourth Rashidun caliph, Ali, and the rebel groups.
Combat between the forces of Ali and Mu'awiyah I during the Battle of Siffin, from the Tarikhnama
A 1909 photograph of the Nahrawan Canal