Eliezer ben Nathan

Eliezer ben Nathan (Hebrew: אליעזר בן נתן) of Mainz (1090–1170), or Ra'avan (ראב"ן‎), was a halakist and liturgical poet. As an early Rishon, he was a contemporary of the Rashbam and Rabbeinu Tam, and one of the earliest of the Tosafists. He was the son-in-law of Rabbi Eliakim b. Joseph of Mainz, a fellow student of Rashi. Through his four daughters Eliezer became the ancestor of several learned families which exerted a great influence upon religious life in the subsequent centuries. One of his great-grandsons was Asher b. Jehiel (ROSH), father of R. Jacob, author of the Ṭurim.

In or around 1160, a synod was held in Troyes as part of the Takkanot Shum. This synod was led by Rabbeinu Tam, his brother, the Rashbam, and the Ra'avan. Over 250 rabbis from communities all over France attended as well. A number of communal decrees were enacted at the synod covering both Jewish-Gentile relations as well as matters relating internally to the Jewish community.