Al-Khawarij (al-Khawarij) is the earliest heretical sect in the history of Islam in the Middle Ages. "Hwareji" means "the one who left" in Arabic , referring to a faction that , the fourth caliph of Islam. The original members of the faction were Arab nomads who joined the army during the four caliphate periods and were stationed in Basra. They belonged to the subordinates of Ali, the fourth caliph, but they had secretly joined the ranks against Uthman. After the third caliph Osman was killed in AD 656, Ali was elected as the fourth caliph. Osman's cousin, the governor of Syria, Mu'awiyah, did not recognize Ali's caliphate status, and raised his troops to demand that the murderer who killed Osman be punished. So in 657 AD, the two sides fought fiercely in the Suifen Plain on the banks of the Euphrates River. In the face of failure, Mu'awiya proposed a truce and demanded "judging by the Qur'an". At that time, in Ali's camp, the main fighters Peach Of Heart were a minority, and most of them advocated peace. Ali himself also favored reconciliation, so he accepted Mu'awiyayi's request for adjudication, and the referees sent by the two sides will conduct the referee. The result of the ruling was the dismissal of the leaders of both parties, placing Ali, the orthodox caliph, on an equal footing with Mu'awiyah. Therefore, it caused extreme dissatisfaction among the main combatants. They believe that Ali's selection as the caliph after Othman was killed was a collective decision of the Muslim commune, that is, Allah's ruling, which is holy, and "there is no other judge except Allah " ; law" is "acts of apostasy" . At that time, about 12,000 people left Ali's team and left, which was called the Hewa Leizhi Pai. In 658 AD, they elected a pious ordinary soldier Abdullah bin Wahab Rahibi (? ~ 658) in the village of Harula near KufaAs the first caliph, he announced that he would not recognize the leadership of Ali and Mu'awiyah in the Islamic society. At first, Ali personally went to Harula village to persuade the faction to return to the group.