For the rest, so far as we can tell, the Arab tribes were not all alike concerned in these wars of conquest. The great camel-breeding tribes of the highlands of the interior, in particular, seem to have taken a much smaller share in them than the tribes of the northern districts of Yemen. It was a point of the utmost importance that the supreme command was almost throughout in the hands of men of the Koreish, who at that time proved themselves a race of born rulers. They led Islam from victory to victory, proving themselves good Moslems on the whole, but without renouncing their worldly wisdom. Above all we are constrained to admire the skill, caution, and boldness with which, from his headquarters at Medina, Omar directed the campaigns and the rudiments of reorganisation in conquered countries.
This unpolished and rigidly orthodox man, who lived with the utmost Arab simplicity while an incalculable revenue was flowing into the treasury of the empire, proved one of the greatest and wisest of sovereigns. His injunction that the Arabs should acquire no landed property in the conquered countries, but should everywhere constitute a military caste in the pay of the state, was grandly conceived, but proved impracticable in the long run. Some of the Christian Arabs at first fought against the Moslem, but without any very great zeal. The majority of them soon exchanged a Christianity that had never gone very deep for the national religion. The great tribe of the Taghlib in the Mesopotamian desert was almost the only one in which Christianity retained its ascendency for any length of time, but it nevertheless fully participated in the fortunes of the Moslem empire, and even there the older faith gradually passed away, as it seems to have done among all Arabs of pure blood.
The victories of the Moslems under Omar were continued under his successor Othman. Syria, Mesopotamia, Babylonia,[21] Assyria, the greater part of Iran proper, Egypt, and some more of the northern parts of Africa were already conquered. The inhabitants of the Roman provinces had almost everywhere submitted to the conquerors without a struggle; in some cases they had even made overtures to them. The deplorable Christological disputes contributed largely to this result: the bulk of the Syrians and Copts were Monophysites and were consequently persecuted in many ways by the adherents of the Council of Chalcedon, who had gained the ascendency at Constantinople. Moreover in other respects the Roman government of the period was not qualified to inspire its Semitic and Egyptian subjects with any great devotion. The rule of the Arabs, though severe, at first was just, and above all they scrupulously observed all treaties whatsoever concluded with them. And the inhabitants of those countries were accustomed to subjection. It is, however, unlikely that they did the victors much positive service beyond occasionally acting as spies, and we must not lay too much stress upon the subjugation of what was on the whole an unwarlike race. Even in Iran, where Islam was confronted by far stronger opposition on national and religious grounds, the bulk of the population, especially in rural districts, offered at most a desultory resistance, while the victors had still many a battle to fight with the forces of the king and the nobles.
CIVIL WARS AMONG THE MOSLEMS