=1. Progress of Mahomedanism.=――There were great changes brought about in the position of the Jews from the spread of the new faith. The followers of Mahomed conquered east and west. First Syria was overrun, and the Christian subjects of the Byzantine Empire driven out of Jerusalem, and a mosque, sacred to Allah, was erected on the ruins of the Jewish Temple and of the Christian church. The power of Persia was broken and finally subdued by the Mahomedans,[8] and their victories over the Persians were rendered the easier by the help and sympathy which they found among the oppressed Persian Jews. Then from Asia the followers of the Prophet turned to Africa, and, establishing themselves in Egypt, looked threateningly across the straits at Spain. Within fifty years of the death of Mahomed the enormous empire of the kaliphs, as his successors were called, extended from the Caspian Sea to the Straits of Gibraltar, and was soon to bridge these, and to come to its greatest triumph in the Peninsula. It was just in these countries that Jews most congregated, and therefore the history of Islam has a special importance for the students of Jewish history. =2. Gaonim.=――The first effect of the Mahomedan supremacy was felt in the neighbourhood where it arose, and chiefly amongst those scholars of Babylon who, within the memories of elderly men, had seen their schools closed and their רֵישׁ נְּלוּתָא hanged. It was no part of the Mahomedan policy to make war on schools. Conquest once assured, the conquered might occupy themselves as they pleased. So long even as contrary beliefs did not take the active form of opposition to Islam, the holders of such beliefs were contemptuously and good-naturedly ignored. It was a pleasant experience for the Jews. Under the tolerant sway of the first kaliph, Omar, who had reason, in his quarrels with the Persians, to make friends with the Jews, the schools were reopened, an heir of the murdered רֵישׁ נְּלוּתָא was reinstated, and the heads of the colleges took on themselves all their old duties and dignities with the new name of Gaonim.[9] Talmudic studies were again revived, and the _kallahs_ (high colleges) of Sora and Pumbaditha grew to be quite celebrated centres of learning. They were diligent students, these Gaonim, and a Gaon called Jehuda, who was blind, and who lived about the year 750, was one of the most active of them all in compiling the laws and decisions contained in the Talmud, and arranging them in systematic order. The Gaonim gradually became the great authorities on all religious and legal questions; and only political matters, and subjects which lay a little outside of the keenest interest, were left to the management of the רֵישׁ נְּלוּתָא. His authority waned again. Some of those who wielded it were not very wise, and managed to come into collision with the Mahomedan rulers. Then from an hereditary dignity it became an elective one, and the succession provoked quarrels. At a certain stage in their history