More from Peter Brown, this from a review of Bowerstock’s Empires in Collision in Late Antiquity : “Bowersock shows, through a combination of archaeological and textual evidence, that the short-lived Sassanian conquest of the Middle East did not leave the former provinces of East Rome desolate. When their armies arrived (in the early 630s) the Arabs ‘did not find a shattered civilization and a ruined economy.’ In fact, they walked into a world as complex and as wealthy as it had ever been, ‘with its rich traditions of Judaism, Christianity, paganism, and Hellenism.’

According to Bowersock, “the Muslims entered the settled lands of the Middle East not only as conquerors, but as well-informed and, even, well-disposed participants in contemporary debates between Christians, Jews, and pagans. For adherents of these religions had penetrated the desert oases of Arabia, largely as a result of the face-off between Jewish Himyar and Christian Axum in the deep south. In an acute analysis of crucial suras (or chapters) in the Koran, Bowersock shows that Muhammad had followed the war between East Rome and Persia with alert eyes. He had acclaimed the victory of the East Roman Empire over the Persians. For he saw in the mighty collision between a Christian and a Zoroastrian empire a mirror image of his own struggle against polytheism in Arabia.”

And he wasn’t seen as a threat when he first occupied Jerusalem in 638. Greek accounts of the occupation “implied that the Muslims appeared to have come as friends rather than as foes. They portrayed the Muslim leader, Umar, as having entered the Holy City, in all sincerity, in the humble dress of a pilgrim anxious to worship at the holy places of fellow monotheists. Only later did Byzantine chroniclers (their attitude toward Islam hardened by centuries of war) dismiss this pious gesture as an act of ‘satanic hypocrisy.’”