The war-expedition consisting of 10,000 Roman troops and several thousand Eastern auxiliaries which the Roman Emperor Augustus despatched in the year 24 B.C. under Aelius Gallus to the southern kingdom of Yemen, for the purpose of securing a direct trade-route to India, appears not to have led to any real conquest. But from the time when Trajan first sent an expedition under his General, Cornelius Palma, against Northern Arabia, which conquered the kingdom of Nabathea, 105, and when he himself, after having subdued Mesopotamia, invaded A.D. Arabia with his victorious army and completely devastated its eastern coast along the Persian Gulf, A.D. 116, Roman influence maintained itself more or less. Several of the Arab chiefs in the northern parts of the country yielded submission, and accepted the position of Roman vassals. Roman historians record that about 536 A.D. the Emperor Justinian conferred the chieftainship of the Arabs of Palestine upon the Emir Abu Karib, in exchange for a country he had possessed on the shores of the Red Sea; and likewise assigned an Arab principality to Kais, a prince of the Kinda tribe. The kingdom of Hira in the north-east of Arabia, though mostly under Persian influence and frequently at war with the Emperor of Constantinople and his allies, had yet also to suffer, at times, from the power of Rome. One of its kings, Munzir iv., who ascended the throne A.D. 580, repaired with his suite to Constantinople to secure the Emperor's favour and support; but afterwards turning against him and siding with the Persians, he was defeated, dethroned, and banished by the Romans. The kingdom of the Ghassanides in North-western Arabia was almost uninterruptedly dependent on the Roman power, since its establishment about the end of the third Christian century till the time of Mohammed.

'The dynasties of Hira and of the Ghassanides were native to Arabia, and it was through them that the Arabs communicated with the external world and received their ideas as well of Europe as of Asia. Hira, moreover, since the fall of the Himyar line in Yemen, became the paramount power of Central Arabia. To this cause, and to the permanence and prosperity of its capital, it was owing that Hira enjoyed a larger political influence than the Ghassanide

kingdom. But the latter, though inferior in magnificence and stability, possessed, especially over the Western Arabs, a more important social power. It lay closer to the Hejaz and in the direct line of its commerce. There was therefore with its prince and people a frequent interchange of civility, both in casual visits at the court and in the regular passage of the mercantile caravans through the country. It is to this quarter therefore, that we must chiefly look for the external influences which moulded the opinion of Mecca and Medina.' Sir W. Muir, from whose able Life of Mahomet the preceding passage is quoted, also further observes: 'It is remarked even by a Mohammedan writer, that the decadence of the race of Ghassan was preparing the way for the glories of the Arabian prophet.'

But this kind of preparation for Mohammed's later exploits and military triumphs to which Mohammedan writers draw attention, is not what we chiefly mean in speaking of a political factor as contributing to the very rise itself of a prophet-king in Mecca and Medina. True, the relatively weakened state of the Empires of Persia and Rome rendered the Mohammedan foreign conquests at all, feasible: but it was the oppressive power they had acquired over great portions of Arabia, and the humiliation this implied for the Arabs, which first of all roused the latter into searching for means by which they might resist the foreigner and recover their own independence. The truer the patriot and the greater his love of country, the more he burned with indignation at the existing state of things, and the more earnestly he cast about for a remedy. The nearer foreign usurpation pressed, the stronger became the incentives to see it removed, and rendered impossible for the future.

Now, when Mohammed had already attained the age of manhood, Roman domination made itself felt for a time in the sacred metropolis of Mecca itself. For shortly after his accession to the throne, A.D. 610, the Emperor Heraclius nominated Othman, then a convert to Christianity and (earlier) a friend and follower of the Hanif Zeid, as Governor of Mecca, recommending him to the Koreishites in an authoritative letter. Othman endeavoured by moderation and kindliness to make himself acceptable with the Meccans. He