"The Arab conquest of Syria in 632–42 was one of the most astonishing accomplishments of its age. In the first place it finally and permanently cut off an eastern wing of the Byzantine Empire, which had been Roman territory for nearly seven hundred years; the border of Byzantium was now pushed back to the Amanus Mountains on the eastern edge of Asia Minor, beyond which it would seldom reach for the rest of the Middle Ages. Much more significantly, though, Syria was one of the first major triumphs of a new power that was about to sweep across the world, branching out to the borders of China and the Atlantic seaboard of Europe, establishing an Islamic state that covered more than twelve million square kilometers. Between Muhammad’s death and the collapse of the Umayyad caliphate in 750, Arab armies appeared everywhere from central Asia, through the Middle East and north Africa, throughout the Visigothic Iberian Peninsula, and even into southern France. They imposed Islamic governments and introduced new ways of living, trading, learning, thinking, building, and praying. The capital of the vast caliphate they established would be Damascus itself, crowned with its Great Mosque—one of the masterpieces of medieval architecture anywhere in the world."