( circa 570–632 ) , Arab prophet and founder of Islam. In circa 610, in Mecca, he received the first of a series of revelations that, as the Koran, became the doctrinal and legislative basis of Islam. In the face of opposition to his preaching, he and his small group of supporters were forced to flee to Medina in 622 (the Hegira). Muhammad led his followers into a series of battles against the Meccans. In 630, Mecca capitulated and by his death Muhammad had united most of Arabia.