(singular - Gaon) Title borne by the heads of the two large academies in Babylonia in Sura and Pumbedita, between the 6th and 11th centuries. In their days the Babylonian Talmud gained wide circulation throughout the Jewish people. The highest religious authorities of their time, they explained the Halacha and established new laws in accordance with contemporary needs. A listing of the Geonim is found in "Iggeret Rav Sherira Gaon" ("The Epistle of Rabbi Sherira Gaon"). The last Gaon in Pumbedita was Rav Hai, the son of Sherira Gaon. The heads of the academies in Eretz Israel at this period were also called Gaon, but their influence was limited. (7.35)