[Footnote 4: The name given to the dynasty founded by Ardeshir, from his pretended ancestor Sassan, a grandson of Isfundear, a hero greatly celebrated in the ancient history of Persia. Isfundear was the son of Gushtasp, who is supposed to be the Darìus Hystaspes of the Greek historians. Sir John Malcolm has endeavoured to identify Isfundear with the Xerxes of the Greeks.] It is the boast of Arabia that it has never been conquered. This immunity from subjugation has, however, been only partial, and is owing to the nature of the country; for although the barren sands of the Hejaz and Nejed have always baffled the efforts of hostile armies, yet the more inviting region of Yemen, the Happy Arabia of the ancients, has more than once allured a conqueror, and submitted to his sway. The inhabitants of this country have been the same in blood and in manners from the dawn of history. Brave, but not sanguinary, robbers, but kind and hospitable, of lively and acute intellect, we find the Arabs, from the days of Abraham to the present times, leading the pastoral and nomadic life in the desert, agriculturists in Yemen, traders on the coasts and on the confines of Syria and Egypt. Their foreign military operations had hitherto been confined to plundering expeditions into the last-mentioned countries, unless they were the Hycsos, or Shepherd Kings, who, according to tradition, once made the conquest of Egypt. Arabia forming a kind of world in itself, its various tribes were in ceaseless hostility with each other; but it was apparent that if its brave and skilful horsemen could be united under one head, and animated by motives which would inspire constancy and rouse valour, they might present a force capable of giving a fatal shock to the empires of Persia and of Rome. It is impossible, on taking a survey of the history of the world, not to recognize a great predisposing cause, which appoints the time and circumstances of every event which is to produce any considerable change in the state of human affairs. The agency of this overruling providence is nowhere more perceptible than in the present instance. The time was come for the Arabs to leave their deserts and march to the conquest of the world, and the man was born who was to inspire them with the necessary motives.