750 MISHNAT HAMIDDOT
The oldest Hebrew treatise on mathematics, it deals with geometric equations. Some attributed it to the 2nd century Rav Nehemiah, but most scholars believe it originated in the middle of the 8th century, although the author is unknown.
750 - 1258 ABBASID DYNASTY (from Abu Abbas) (Persia)
Expanded intellectual horizons and world trade. The Abbasids gained control
from the Umayyads after the assassination of Marwan II in Egypt and moved
the control to Baghdad. Eighty members of Marwan II's family were also
killed at Antipatris near present day Rosh Haayin. Abd ar-Rahman, one of
the surviving members of the Umayyads, reached Cordova and set up his own
Caliphate (see 756). The Abbasids gave more power to the Persians and
Turkish tribes, with Caliphs taking upon themselves absolute authority.
Although, as with the Umayyad Dynasty, the Jewish position depended on the
current ruler, in general, Jews began to play an important role in world
trade and banking.
756 - 788 ABD AR-RAHMAN I (Abd Al-Rahman I) (Spain)
An Umayyad caliph, he made Spain independent of Baghdad. His court was open to poets, scientists, and philosophers. At the same time that the influence of Babylon was waning, Spain was becoming the center of Jewish thought. The Umayyad rule in Spain was to last 250 years and provide peace and stability for its inhabitants.
757 - 761 RAV JUDAH (Yehudai) GAON OF SURA (Babylon)
Also known as Judah the blind. He was one of the leading presenters of the liturgy, or Shliach Tzibbur, and favored the new practice of professional cantorship (hazzanut). He recommended that an ABA (ternary) musical format be used , so that beginning and end of each piece be similar, with some variance in the middle. He also introduced the chanting of Kol Nidre into the synagogue. Yehudai wrote the first work on traditional law since the completion of the Talmud, called Halachot Ketuot and probably Halachot Pesukot as well.He was a vociferous proponent of the acceptance of the Babylonian Talmud rather than the Jerusalem Talmud as the basis for all halacha.
759 NARBONNE (Carolingian Empire)
Moorish occupation ended after just 39 years. During this brief time the Jewish population greatly increased. They played a pivotal role in the formal occupation of the city by Charlemagne, who granted them 1/3 of the town under their own ruler (Nasi).