Abu Bekr and Omar I are the two master figures in the history of Islam. It is not within our scope here to describe the wars by which in a hundred and twenty-five years Islam spread itself from the Indus to the Atlantic and Spain, and from Kashgar on the borders of China to Upper Egypt. Two maps must suffice to show the limits to which the vigorous impulse of the new faith carried the Arab idea and the Arabic scriptures, before worldliness, the old trading and plundering spirit, and the glamour of the silk robe had completely recovered their paralyzing sway over the Arab intelligence and will. The reader will note how the great tide swept over the footsteps of Yuan Chwang, and how easily in Africa the easy conquests of the Vandals were repeated in the reverse direction. And if the reader entertains any delusions about a fine civilization, either Persian, Roman, Hellenic, or Egyptian, being submerged by this flood, the sooner he dismisses such ideas the better. Islam prevailed because it was the best social and political order the times could offer. It prevailed because everywhere it found politically apathetic peoples, robbed, oppressed, bullied, uneducated, and unorganized, and it found selfish and unsound governments out of touch with any people at all. It was the broadest, freshest, and cleanest political idea that had yet come into actual activity in the world, and it offered better terms than any other to the mass of mankind. The capitalistic and slave-holding system of the Roman Empire and the literature and culture and social tradition of Europe had altogether decayed and broken down before Islam arose; it was only when mankind lost faith in the sincerity of its representatives that Islam too began to decay.
The larger part of its energy spent itself in conquering and assimilating Persia and Turkestan; its most vigorous thrusts were northwardly from Persia and westwardly through Egypt. Had it concentrated its first vigour upon the Byzantine Empire, there can be little doubt that by the eighth century it would have taken Constantinople and come through into Europe as easily as it reached the Pamirs. The Caliph Moawiya, it is true, besieged the capital for seven years (672 to 678), and Suleiman in 717 and 718; but the pressure was not sustained, and for three or four centuries longer the Byzantine Empire remained the crazy bulwark of Europe. In the newly Christianized or still pagan Avars, Bulgars, Serbs, Slavs, and Saxons, Islam would certainly have found as ready converts as it did in the Turks of Central Asia. And though, instead of insisting upon Constantinople, it first came round into Europe by the circuitous route of Africa and Spain, it was only in France, at the end of a vast line of communications from Arabia, that it encountered a power sufficiently vigorous to arrest its advance.
From the outset the Bedouin aristocrats of Mecca dominated the new empire. Abu Bekr, the first Caliph, was in an informal shouting way elected at Medina, and so were Omar I and Othman, the third Caliph, but all three were Meccans of good family. They were not men of Medina. And though Abu Bekr and Omar were men of stark simplicity and righteousness Othman was of a baser quality, a man quite in the vein of those silk robes, to whom conquest was not conquest for Allah but for Arabia, and especially for Mecca in Arabia, and more particularly for himself and for the Meccans and for his family, the Omayyads. He was a worthy man, who stood out for his country and his town and his “people.” He was no early convert as his two predecessors had been; he had joined the Prophet for reasons of policy in fair give and take. With his accession the Caliph ceases to be a strange man of fire and wonder, and becomes an Oriental monarch like many Oriental monarchs before and since, a fairly good monarch by Eastern standards as yet, but nothing more.