While still young, Ashi became the head of the Sura Academy, his great learning being acknowledged by the older teachers. It had been closed since Hisda's death (309), but under Ashi it regained all its old importance. His commanding personality, his scholarly standing, and wealth are sufficiently indicated by the saying, then current, that since the days of Judah I the Patriarch, "learning and social distinction were never so united in one person as in Ashi." Indeed, Ashi was the man destined to undertake a task similar to that which fell to the lot of Judah I,. The latter compiled and edited the Mishnah; Ashi made it the labor of his life to collect after critical scrutiny, under the name of Gemara, those explanations of the Mishnah that had been handed down in the Babylonian academies since the days of Rab, together with all the discussions connected with them, and all the halachic and haggadic material treated in the schools.
Conjointly with his disciples and the scholars who gathered in Sura for the "Kallah," or semi-annual college conference, he completed this task. The kindly attitude of King Yezdigerd I, as well as the devoted and respectful recognition of his authority by the academies of Nehardea and Pumbedita, greatly favored the undertaking. A particularly important element in Ashi's success was the length of his tenure of office as head of Sura Academy, which must have lasted fifty-two years, but with tradition, probably for the sake of round numbers, was exaggerated into sixty. According to the same tradition, these sixty years are said to have been so symmetrically apportioned that each treatise required six months for the study of its Mishnah and the redaction of the traditional expositions of the same (Gemara), thus aggregating thirty years for the sixty treatises. The same process was then repeated for thirty years more, at the end of which period the work was considered complete.
The artificiality and unreality of this legendary account are made clear by the facts that the treatises are of different degrees of length and difficulty, and that a large number of them possess no Gemara whatsoever. Probably all that is historical in this statement is that Ashi actually revised the work twice – a fact that is mentioned in the Talmud. Beyond this, the Talmud itself contains not the slightest intimation of the activity which Ashi and his school exercised in this field for more than half a century. Even the question as to whether this editorial work was written down, and thus, whether the putting of the Babylonian Talmud into writing took place under Ashi or not, cannot be answered from any statement in the Talmud. It is nevertheless probable that the fixation of the text of so comprehensive a literary work could not have been accomplished without the aid of writing. The work begun by Ashi was continued in the two succeeding generations and completed by Rabina, another president of the college in Sura, who died in 499. To the work as the last-named left it, only slight additions were made by the Saboraim. To one of these additions – that to an ancient utterance concerning the "Book of Adam, the First Man," – this statement is appended: Ashi and Rabina are the last representatives of independent decision (hora'ah'')," an evident reference to the work of these two in editing the Babylonian Talmud, which as an object of study and a fountainhead of practical "decision" was to have the same importance for the coming generations as the Mishnah had had for the Amoraim.
Ashi not only elevated Sura till it became the intellectual center of the Babylonian Jews, but contributed to its material grandeur also. He rebuilt Rab's academy and the synagogue connected with it, sparing no expense and personally superintending their reconstruction. As a direct result of Ashi's renown, the Exilarch came annually to Sura in the month after the New Year to receive the respects of the assembled representatives of the Babylonian academies and congregations. To such a degree of splendor did these festivities and other conventions in Sura attain that Ashi expressed his surprise that some of the Gentile residents of Sura were not tempted to accept Judaism.
Sura maintained the prominence conferred on it by Ashi for several centuries, and only during the last two centuries of the Gaonic period did Pumbedita again become its rival. Ashi's son Tabyomi, always spoken of as "Mar (Master), the son of Rab Ashi," was a recognized scholar, but it was not until 455, twenty-eight years after his father's death, that he was invested with the position that his father had so successfully filled for more than half a century.
This article was taken from the Jewish Encyclopedia (1903).