The Rivam (c. 1090 – c. 1130), Rabbi Yitzchak ben Meir, was one of the Baalei Tosafos. He was the grandson of Rashi, and brother of the Rashbam and the Rabbeinu Tam. His father was Meir ben Shmuel and his mother was Yocheved, the daughter of Rashi. He died before his father, leaving four children (Jacob Tam, Sefer ha-Yashar, No. 616, p. 72b, Vienna, 1811). Although he died young, the Rivam contributed to Tosafos, mentioned by Eliezer b. Joel ha-Levi (Abi ha-'Ezri, §417), to several tractates of the Talmud. Isaac himself is often quoted in the edited Tosafos (Shab. 138a; Ket. 29b et passim).

Further reading

• The Rishonim, published by Artscroll (contains short biographies of the Rishonim including the Rivam)