KHAWARIJ خوارج
Lit. “The Revolters.” A sect of Muslims who affirm that any man may be promoted to the dignity of Khalifah, even though he be not of the Quraish tribe, provided he be elected by the Muslim nation. The first who were so-called were the 12,000 men who revolted from ‘Ali after they had fought under him at the battle of Siffin, and took offence at his submitting the decision of his right to the Khalifate to the arbitration of men when, in their opinion, it ought to have been submitted to the judgement of God. They affirmed that a man might be appointed Khalifah, no matter of what tribe or nation, provided he were a just and pious person, and that if the Khalifah turned away from the truth, he might be put to death or deposed. They also held that there was no absolute necessity for a Khalifah at all. In A.H. 38, large numbers of this sect were killed, but a few escaped, and propagated their schism in different parts of the world. [KHALIFAH.]

Based on Hughes, Dictionary of Islam