Polish Talmudist; born in the second decade of the seventeenth century; died at Metz March 20, 1693. His family name was really V02p197001.jpg, "Ulif," "Olive"(?), the surname "Ashkenazi" being usually bestowed in Poland upon families of German extraction. Gershon Ashkenazi was also named "Poss"—not "Fass"—after his rich father-in-law, Loeb Poss, of Cracow. He was dayyan in Cracow, possibly his birthplace, at all events the place where he obtained his Talmudic education from Joel Särkes and Joshua Ḥarif. From 1649 to 1659 he was rabbi at Prossnitz, from 1659 to 1660 at Hanau, and from 1661 to 1664 at Nikolsburg, where he succeeded his father-in-law, Menahem Mendel Krochmal. For the next five years he was rabbi at Vienna, but was forced to leave owing to the banishment of the Jews. Thence he went to Metz in 1670, where he remained until his death.

Although rabbi of large communities and head of a yeshibah, Ashkenazi found time for literary activity. Of his numerous works, the following have been printed: (1) "'Abodat ha-Gershuni" (Gershon's Service), containing his responsa to the principal Talmudists of his day. The number of these responsa is 124; and they contain much information upon the condition of the Jews in Poland, after the persecutions by the Cossacks; (2) "Tiferet ha-Gershuni" (Gershon's Ornament), midrashic and cabalistic expositions of the Pentateuch. Both books were published at Frankfort-on-the-Main in 1699. (3) "Ḥiddushe ha-Gershuni" (Gershon's Novellæ), Frankfort-on-the-Main, 1716, containing remarks and explanations concerning the third and fourth books of the ShulḦan 'Aruk, in which the author severely criticizes the AḦaronim.

Even in his lifetime Ashkenazi was recognized as an authority in Talmudic lore, and especially as a most eminent dialectician. His works scarcely justify this opinion; for they are not much above the general average of the rabbinical literature of his time. His influence was, nevertheless, considerable, and was due to his personality. The many ritual inquiries directed to him while rabbi of Metz from western Germany and Alsace-Lorraine show that after his advent in that city he was really the spiritual and intellectual authority for the Jews of those countries. It was mainly in Metz that he exercised a many-sided influence as teacher. Ashkenazi was deeply revered and loved by a large number of pupils whom he had the power to attract to himself. Chief among these was David Oppenheim(er).

Ashkenazi was the father of four learned sons, Moses, Nathan, Nahum, and Joel, of whom the first-named gained prominence as a Talmudist and cabalist. He died March 22, 1691, at Nikolsburg.