(c. 1100-1171), Rabbi Jacob ben Meir Tam, commonly referred to (as a sign of admiration) as Rabbenu Tam1, was a tosafist and a leading Jewish French scholar.

Rabbenu Tam was the grandson of Rashi, and the son of Meir ben Samuel, Rashi's son-in-law. His teachers were his father, and some of Rashi's greatest pupils. Little is known about members of his family, except that his wife, Miriam, was the sister of Rav Jacob ben Samson of Falaise and that four of his sons were named Joseph, Moses, Solomon, and Isaac, about whom nothing is known. Rabbenu Tam lived in Ramerupt, where he engaged in moneylending and viticulture, typical occupations of a Jew there at that time, and became well-to-do. His business affairs brought him into contact with the nobility and the authorities, who occasioned him much trouble. To a great extent his attitude toward non-Jews in various Halachic questions was conditioned by his direct contact with them and his knowledge of their character. During the Second Crusade he was attacked by Crusaders who were passing through, and was miraculously saved from death (1146). After this attack he left Ramerupt.

Tam was recognized by all contemporary Jewish scholars, even those in remote and far away places, as the greatest scholar of his generation, and his Halachic interpretations and rulings were yielded to by virtually all the Jewish world. His Beit Midrash (Jewish religious school) attracted pupils from all of Europe, which helped spread his teachings from Spain to Russia. He won this greatest renown even though he never moved or traveled far from his home in Northern France. Tam was not unaware of the fame he has gained, and based on it the claim that his religious court had the authority to issue decisive pronouncements. He violently attacked scholars, even in distant places, who refused to accept his pronouncements, revealing a disire to impose his Halachic authority also on Provence and Germany, a tendency opposed vehemently by Rav Abraham ben David of Posquières. Tam also did not hesitate to threaten with excommunication against anyone who opposed his Halachic rulings, or who adopted the customs of those who disagreed with him.

Rabbenu Tam proved to be a rather high-handed leader of his generation, who did not refrain either from abolishing several customs which did not appeal to him, or from introducing important ordinances and legal permissions dictated by the times. Dispite this, overall he was extremely conservative on questions of custom.

The Tosafot of the Babylonian Talmud are based on Tam's explanations, glosses, and decisions, and are pervaded throughout with his statements. In addition to this, his literary production was large and ramified. His principal work is Sefer HaYashar, which consists of two parts, the fist being a responsa, and the second, novellae on the Talmud. But this work contains only a small part of his responsa, others being scattered throughout the entire literature of earlier Halachic authorities, and in various manuscripts. There is still no complete edition of his responsa. The main trend of his novellae is to corroborate the Talmudic texts and to prove that nothing is to be emended, either by deletion or addenda, whether on the basis of logical argument or on that of other works and parallel sources. Preserved in an extremely corrupt state, Sefer HaYashar, even after the great effort expended on editing it since the 1810's, still contains many obscure and inexplicable pasages.

Earlier authorities also refer to Tam's Sefer HaPesakim, which is no longer extant. It is doubtful whether he wrote a special commentary on the Torah, although biblical comments of his are quoted by many of the earlier tosafists. It is, however, clear that he composed a commentary on the Book of Job. Another of his extant works is Hilkhot Sefer Torah.

Tam was also the first Jewish French scholar to compose rhymed poetry in Hebrew, in which he was undoubtedly influenced by the Spanish scholars with whom he came into contact. He exchanged poems with Abraham ibn Ezra. His piyutim were written largely in the Franco-German style. Tam also wrote a didactic poem on the cantillation of the Torah.

Tam also devoted himself to Hebrew grammer. His Sefer Hakhra'ot, the purpose of which was to decide the points in the dispute in grammer between Menahem ibn Saruk and Dunash ben Labrat, is particularly well known. Tam was mostly on ibn Saruk side. Tam's knowledge of grammer was far from perfect, and it is doubtful that he discovered the triliteral nature of the Hebrew root independently of Judah ben David Hayuj, as was suggested by some.


1"Rabbenu" is Hebrew for 'our Rav', Rav is the Jewish religious title (Rabbi in English, which is actually a transliteration of the Hebrew 'my Rav'), but literally means 'Teacher' in addition to being a title for a spiritual leader.