[2] Known as "Rabbeinu" (our teacher), he acquired the Hebrew suffix "Tam" meaning straightforward; it was originally used in the Book of Genesis to describe his biblical namesake, Jacob.

He maintained a scholarly correspondence with Aaron ben Joseph of Beaugency and received questions from students throughout France and from the Italian communities of Bari and Otranto.

Rabbeinu Tam gave his Beth Din the title of "the generation's [most] significant court", and indeed, he is known for communal enactments improving Jewish family life, education, and women's status.

The rise and articulation of chasidic philosophy has conflated the kabbalistic and halakhic aspects of Rabbeinu Tam's position, popularizing the custom to wear both pairs every day.

Wearing Rabbeinu Tam tefillin is an almost universal custom among the many and diverse communities that follow the teachings of the Baal Shem Tov and his students.

He was influenced by the poetry of the Spaniards, and is the chief representative of the transition period, in Christian lands, from the old "payyeṭanic" mode of expression to the more graceful forms of the Spanish school.

[11] It must, however, be remarked that there was a synagogal poet by the name of Jacob ben Meïr (Levi) who might easily have been confounded with the subject of this article, and therefore Tam's authorship of all of these poems is not above doubt.

Another work of his in metric form is his poem on the accents, which contains forty-five strophes riming in; it is found in various libraries (Padua, Hamburg, Parma), and is entitled Maḥberet.

In 2005, Rabbi Yisroel Meir Gabbai, a Breslover Hasid who renovates and repairs neglected gravesites of Jewish leaders around the world, helped to determine the exact boundaries of the cemetery.

[13] Rabbeinu Tam's best known work is Sefer HaYashar, which contained both novellae and responsa, its main purpose to resolve Talmudic textual problems without resorting to emendations of the received text.