Yehudai ben Nahman was the head of the yeshiva

Yeshiva

Yeshiva is a Jewish educational institution that focuses on the study of traditional religious texts, primarily the Talmud and Torah study. Study is usually done through daily shiurim and in study pairs called chavrutas...

 in Sura

Sura (city)

Sura was a city in the southern part of ancient Babylonia, located west of the Euphrates River. It was well-known for its agricultural produce, which included grapes, wheat, and barley...

 from 757

757

Year 757 was a common year starting on Saturday of the Julian calendar. The denomination 757 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.-Africa:* Foundation of the city of Sijilmasa by the...

 to 761

761

Year 761 was a common year starting on Thursday of the Julian calendar. The denomination 761 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Telets succeeds Vinekh as king of...

, during the Gaonic

Geonim

Geonim were the presidents of the two great Babylonian, Talmudic Academies of Sura and Pumbedita, in the Abbasid Caliphate, and were the generally accepted spiritual leaders of the Jewish community world wide in the early medieval era, in contrast to the Resh Galuta who wielded secular authority...

 period of Judaism

Judaism

Judaism ) is the "religion, philosophy, and way of life" of the Jewish people...

. He was originally a member of the academy of Pumbedita

Pumbedita

Pumbedita was the name of a city in ancient Babylonia close to the modern-day city of Fallujah....

, but the exilarch

Exilarch

Exilarch refers to the leaders of the Diaspora Jewish community in Babylon following the deportation of King Jeconiah and his court into Babylonian exile after the first fall of Jerusalem in 597 BCE and augmented after the further deportations following the destruction...

 Solomon ben Hisdai appointed him as Gaon of Sura as "there is no one there (at Sura) as distinguished as he is for wisdom".

He waged a strong campaign, continued by his disciple Pirkoi ben Bavoi, for the acceptance of the Babylonian Talmud

Talmud

The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....

 as the standard for Jewish law in all countries. This was opposed by the Jews of Eretz Yisrael, who relied on the Jerusalem Talmud

Jerusalem Talmud

The Jerusalem Talmud, talmud meaning "instruction", "learning", , is a collection of Rabbinic notes on the 2nd-century Mishnah which was compiled in the Land of Israel during the 4th-5th century. The voluminous text is also known as the Palestinian Talmud or Talmud de-Eretz Yisrael...

 and their own older traditions. Yehudai argued that, as a result of Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 persecution, the Jews of Eretz Yisrael had only preserved Jewish tradition in a fragmentary and unreliable form.

Works

He was author of the book Halachot Pesukot, which discusses those halachot that were practiced in the Diaspora

Diaspora

A diaspora is "the movement, migration, or scattering of people away from an established or ancestral homeland" or "people dispersed by whatever cause to more than one location", or "people settled far from their ancestral homelands".The word has come to refer to historical mass-dispersions of...

 since the destruction of the Second Temple

Second Temple

The Jewish Second Temple was an important shrine which stood on the Temple Mount in Jerusalem between 516 BCE and 70 CE. It replaced the First Temple which was destroyed in 586 BCE, when the Jewish nation was exiled to Babylon...

. The text, which is generally organized along the same pattern as the tractates of the Babylonian Talmud, was the subject of many abridgements and summaries. The original was lost for many years, and was only known in the form of a Hebrew paraphrase called Hilchot Re'u (published Versailles 1886), until it was discovered in a Yemenite manuscript and published in Jerusalem in 1950.

One current of rabbinic and scholarly opinion also credits him with authorship of the Halachot Gedolot, or of the core of it, though it is generally agreed that the final form of that work is to be attributed to Simeon Kayyara

Simeon Kayyara

Simeon Kayyara was a Jewish-Babylonian halakist of the first half of the 9th century. The early identification of his surname with "Qahirah," the Arabic name of Cairo , was shown by J.L. Rapoport to be impossible. Neubauer's suggestion Simeon Kayyara (Hebrew: שמעון קיירא) was a ...

. At all events the Halachot Pesukot was an important source for the larger work.