One of the books on Cantor's long list is Medieval Islam, A Study in Cultural Orientalism by Gustave E. Von Grunebaum, 2nd ed 1953. On page 4, Von Gunebaum writes, "In exactly one hundred years, between the death of the Prophet in 632 and the Battle of Tours and Poitiers, Islam carved out its dominion. During the last ten years of his life Mohammad had built up a state centered on Medina firmly controlling the Hijaz and parts of the Najd and more loosely imposing its authority on other sections of Arabia proper. His death was the signal for the nominally converted Bedouins to revolt. When this centrifugal movement had been crushed, expansion set in with incredible swiftness. Syria was torn from the Byzantines, weak and weary after a bitter struggle with Persia and even more embittered religious controversies within. In 638 Jerusalem fell. Only two years later Egypt was invaded, its conquest sealed when Alexander surrendered in 647. In the meantime Persia had been overrun, and the Battle of Nihavand (641) had put an end to effective large-scale resistance, although it took another decade before the power of the last Sassanian ruler was completely eliminated and the king himself a disgruntled subject (651). "The chronology of the Arab movement to the West is not entirely clear, but in 670 the soldiers of the caliph had advanced into what is today Tunisia and founded the city of Qairawan. Determined resistance of the native Berbers and the Byzantine garrisons in various seacoast towns slowed up the Arab advance, but by about 700 the country had been cleared of Greek troops and the Berbers subdued. It seems that a sizable percentage of the Latinized and Hellenized population of the cities emigrated to Spain and Sicily. At any rate, the vestiges of ancient civilization were quickly obliterated. "Only ten years later Africa was sufficiently secure for the Arabs to use it as a base for an attack on Spain. In July, 711, the Visigoth Kingdom collapsed in the defeat of its army at Jerez de la Frontera. A few more years and the Arabs felt strong enough to cross the Pyrenees. But despite temporary successes on French soil, where they maintained themselves for about half a century in the south around Narbonne, their aggressive impulse was spent after they had met defeat at the hands of the Franks." It should be noted that Constantinople is not on the list of conquered Christian lands. That didn't occur until much later (see The Fall of Constantinople, 1453 by Steven Runciman). The Byzantine Empire was subjected to ongoing pressure from the Turks. It was that pressure that ultimately caused the cry for help that resulted in the Pope's much-belated response: a call for a crusade. Lawrence