חיים כהן (מבעלי התוספות)

Rabbeinu Chaim ben Chananel HaKohen (twelfth century) was among the early baalei Tosafot and the senior talmid of Rabbeinu Tam — the elder of that extraordinary beit medrash, whom his fellow talmidim treated as first among them. The R”I himself wrote of him: “my teacher Rabbeinu Chaim, upon whom the honor of the entire generation rests… the beit din of my teacher Rabbeinu Chaim is like the great beit din.” In Rabbeinu Tam’s house he took an active part in the drafting of his rebbe’s teshuvot, and the baalei Tosafot — the R”I HaLavan, his brother-in-law Rabbi Eliyahu of Paris, and others — sent him their questions; his words stand dozens of times in the Tosafot printed on the page of the Gemara.

His reverence for his rebbe became halachah: he said that had he been present at Rabbeinu Tam’s passing he would have made himself tamei for him, kohen though he was — for the gadol hador is as the ones for whom a kohen may mourn, as Rabbi Chiya said at the passing of Rabbeinu HaKadosh. The statement preserves both the awe and the psak.

His wife’s sisters married Rabbi Eliyahu of Paris, Rabbeinu Yaakov of Corbeil — and Rabbeinu Yom Tov of Joigny, the kadosh of York. His sons wrote on the piyutim of the machzor; and his daughter’s son was Rabbeinu Moshe of Coucy, author of the Sefer Mitzvot Gadol, who cites him with the words: “Rabbeinu Chaim Kohen Gadol, my mother’s father.”