ר"י הזקן

Rabbeinu Yitzchak ben Shmuel of Dampierre (c. 4875/1115–c. 4950/1190), known as the Ri HaZaken and simply as Rabbeinu Yitzchak Baal HaTosafot, was among the earliest and greatest of the Baalei HaTosafot. On his mother’s side he was a great-grandson of Rashi — she was a daughter of Rabbeinu Meir ben Shmuel and Yocheved bas Rashi, and a sister of the great brothers Rabbeinu Tam, the Rashbam and the Rivam — and his father was Rabbeinu Shmuel HeChasid of Vitry. He was called the elder, HaZaken, to set him apart from his own great talmid Rabbeinu Yitzchak of Sens, the Ritzva, who was called the younger.

He learned first under his uncle the Rivam, who was niftar young, and then in the yeshiva of his uncle Rabbeinu Tam in Troyes, to whom he was bound in deep closeness; the two would contend in halachah, and where the Ri was right, Rabbeinu Tam would concede to him. He founded a yeshiva in Ramerupt and later moved it to Dampierre. When Rabbeinu Tam was niftar in 4931/1171, the Ri — by then past fifty — became the gadol hador, and many of his uncle’s talmidim came to him, foremost Rabbeinu Shimshon of Sens and the Ritzva. Dampierre became the great workshop of the Tosafot; it was said he had sixty pupils, each of whom knew a full masechta by heart, so that the whole Shas lay stored among them.

He gathered the many collections of Tosafot that became the foundation of the entire enterprise, beginning with the Tosafot Yeshanim, and answered a great many she’elot sent to him from across Europe; he is quoted on nearly every page of the Tosafot. In 4944/1184 his son Rabbi Elchanan, one of his own leading talmidim, was killed al kiddush Hashem — a bitter blow to the father, who raised in his home the orphaned grandson born that same year. The Ri HaZaken was niftar in his old age and buried in Ramerupt (France); Rabbeinu Shimshon of Sens is counted his principal successor.