Under Mohammed's successor Abu Bekr, there was a momentary falling-off, but the movement rallied under the leadership of Omar who followed the master's policy of spreading the new Faith by conquest. At the head of the Mosque, (the Church of Islam) was now an emperor--a caliph. Not so many years after Mohammed's death not only was most of Arabia Moslem, but the sway of Islam had reached Persia, conquered the land and superseded Zoroastrism. Syria and Egypt were next wrestled from the Byzantian or Eastern Roman Empire. Palestine had been taken from Persia by the Byzantines in 628 only to be lost again in 638 and in both wars the long-suffering Jews who saw their old home tossed from one conqueror to another, had looked to the incoming enemies as deliverers, (pp. 282-3). What changes had Jerusalem seen! When the Jewish Temple was destroyed, it became a heathen capital--Aelia Capitolina, adorned with a heathen shrine. In its Christian era it became a bishopric. Under the Mohammedans a mosque held the place of honor. Such it remains to-day. Islam was now accepted in Asia, as Christianity had been accepted in Europe, not by individuals, but by whole nations. Somewhat intolerant at first against opposing creeds--some of the Mussulmen were fanatics--it became later renowned for its breadth and enlightenment. Very soon the Jews found the Mohammedans their friends, against whom they had nothing to fear. Jewish poets began to hail their advent. Even in Babylonia the Moslem sway was more liberal than had been that of the Persian Magi in the latter years. The political, social and religious status of the Jews was to remain undisturbed; the same secular official was to be at their head (pp. 231, 233). In fact, the Resh Galutha was given even heartier endorsement, and was treated as a prince by the government, with his civil and judicial powers increased, making the Jewish community in Babylonia almost a State in itself. It was the Caliph Omar who, in 638 raised Bostonai, a descendant of the House of David, to the post of Resh Galutha (Exilarch). The academies at Sora and Pumbeditha were continued without a break; their heads, called _Geonim_ (Illustrious) had also certain powers and took equal rank with the Resh Galutha. The Jews became loyal subjects of the Mohammedan rulers, and when Caliph Ali's successor was deposed by a rival house (for Islam had also now split into two wings), the Jews came gallantly to his support. Here and there Moslem law in its freshest and noblest expression reacted favorably even on Jewish law. New religious movements in early stages of enthusiasm always reach high moral levels. It will be borne in mind that the Jews in all their past experience were necessarily influenced to a degree by their environment, while remaining loyal in all essentials to the traditional conception of Jewish life.