Rabbenu Eliezer ben Nassan ben Nassan, REBAN

Eliezer ben Nathan‬ (Hebrew: אליעזר בן נתן‬) of Mainz (1090–1170), or Ra'aven (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 R. Asher b. Jehiel (ROSH), father of R. Jacob, author of the Ṭurim.

https://www.sefaria.org/person/Ra'avan