But already there was another tempest gathering, which was destined to sweep over the Roman empire, with even greater violence than the Persian storm which had just been weathered. While in the midst of his last campaign, Heraclius had received a letter from an obscure Arabian prophet, bidding him accept a new revelation from Heaven, which its framer called ‘Islam,’ or ‘Submission to God.’ A similar missive was delivered at the same moment to Chosroes, then on the eve of his fall. Chosroes tore up the letter, and swore he would, at his leisure, lay the insolent prophet in a dungeon. Heraclius sent a polite letter of acknowledgment and a trifling present to the unknown fanatic, being averse to making enemies of any sort while the Persian war was still on his hands. Little as it could have been foreseen at the time, the followers of the writer of these eccentric missives were fated to tear up the empire of Chosroes by the roots, and to lop off half of its fairest provinces from the realm of Heraclius. The Arabian prophet was no less a person than Mohammed the son of Abdallah, that strange being, half seer and half impostor, whose preaching was destined to convulse three continents, and turn the stream of history into new and unexpected channels. [Sidenote: Mohammed.] The tribes of Arabia had hitherto been of very little importance: their local feuds absorbed all their superfluous energy. They were divided from each other, as well by religious differences as by ancient clan hatreds. Some worshipped stocks and stones, some the host of heaven, some had partly adopted Christianity, others Judaism. They were given over to fetich-worship, human sacrifices, drunkenness, infanticide, bloodshedding, polygamy, and highway robbery. Among these godless tribes appeared Mohammed, a poor man, but born of an ancient and powerful clan, who preached to them a rigid Unitarian creed, accompanied by a reformation in morality. He had been called by the One true God, he said, in a vision on Mount Hira, to proclaim a new revelation to his countrymen, to turn them from idolatry and hatred of each other, to the worship of Allah and the practice of brotherly love. Mohammed was a being of a poetic and visionary temperament, given to high ideals and high enterprises. He was afflicted with long fits, or trances, in which his soul wandered far into the fields of thought: these trances he took for divine inspirations, and his imaginings—which were often noble enough—seemed to him the direct commands of God, though in them good and grand ideas were freely mixed with baser elements, tainted by the ignorance, cruelty, and lust of a seventh century Arab. For long the preaching of Mohammed was of no effect: his own tribe grew weary of his unending exhortations, and chased him away from Mecca (622). [Sidenote: The Hijrah, 622.] It is from this flight to Medina—the famous ‘Hijrah,’ that all Moslem chronology is dated. But in spite of ill-success and persecution the