ראב"ן

Eliezer ben Nathan of Mainz (1090–1170), or Ra'avan, 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 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 ben Jehiel (Rosh), father of R. Jacob, author of the Ṭurim.