In the increasingly unfriendly climate of Christendom, Jews were consoled by the knowledge that in nearby Babylonia (then under Persian rule) a vast population of Jews lived under a network of effective and autonomous Jewish institutions and officials. Steadily worsening conditions in Palestine drew many Jews to Persian domains, where economic opportunities and the Jewish communal structure enabled them to gain a better livelihood while living in accordance with their ancestral traditions. To regulate internal Jewish affairs and ensure the steady flow of taxes, the Parthian, or Arsacid, rulers (247 bce–224 ce) had appointed in approximately 100 ce an exilarch, or “head of the [Jews in] exile”—who claimed more direct Davidic descent than the Palestinian patriarch—to rule over the Jews as a quasi-prince. About 220, two Babylonian disciples of Judah ha-Nasi, Abba Arika (known as Rav) and Samuel bar Abba, began to propagate the Mishna and related tannaitic literature as normative standards. As heads of the academies at Sura and Nehardea, respectively, Rav and Samuel cultivated a native Babylonian rabbinate, which increasingly provided the manpower for local Jewish courts and other communal services. While the usual tensions between temporal and religious arms frequently existed in Babylonia, the symbiosis of exilarchate and rabbinate endured until the middle of the 11th century.

Paradoxically, Babylonian rabbinism derived its theological and political strength from its fundamentally unoriginal character. As a transplant of Palestinian Judaism, it asserted its historical legitimacy to the Sāsānian dynasty (224–651), who protected Jewish practices against interference from fanatical Magian priests, and to native Jewish officials, who argued for the validity of indigenous Babylonian deviations from Palestinian norms. But ultimately the historical importance of this transplantation lay in Babylonia’s serving as the proving ground for the adaptability of Palestinian Judaism to a Diaspora situation. Legal and theological adaptations generated by the new locale and the needs of the times inevitably produced changes in the religious tradition. The laws of agriculture, purity, and sacrifices all of necessity fell into disuse. The principles embodied in these laws, however, and the core of the legal and theological system—consisting of faith in the revelation and election of Israel, the requirement that the individual live by the canons of Jewish civil and family law, and the network of communal institutions modeled on those of Palestinian Judaism—remained intact, thereby ensuring a basic continuity and uniformity among rabbinically oriented communities everywhere. Because historical circumstances made Babylonia the mediator of this tradition to all Jewish communities in the High Middle Ages (9th–12th centuries), the Babylonian version of Jewish religion became synonymous with normative Judaism and the measure of Judaic authenticity everywhere.

“The law of the [Gentile] government is binding”—the principle formulated by Samuel (died 254), head of the academy at Nehardea—summarizes the essential novelty in rabbinic reorientation to life on foreign soil. Whereas Palestinian rabbis had complied with imperial decrees of taxation as legitimate de facto—and this was all that Samuel had in mind—Babylonian teachers now rationalized governmental authority in this respect as legitimate de jure, thus enjoining upon the Jews political quietism and submissiveness as part of their religious doctrine. In all other areas of civil law, the Jews were instructed by their rabbis to file suit in Jewish courts and thus to conduct their businesses as well as their family lives by rabbinic law.

While the rabbis could impose their discipline more effectively in matters of public law than in private religious practice, the density of the Jewish population in many areas of Parthia (northeastern Iran) and Babylonia facilitated the application of moral and disciplinary pressures. The most effective vehicle for the dissemination of their teachings was the academies, where judges and communal teachers were trained; among these institutions, those of Sura and Pumbedita remained preeminent. Frequent public lectures in the synagogues of the academies on Sabbaths and festivals were capped by public kalla (study-course) assemblies for alumni of the schools during the two months, Adar (February–March) and Elul (August–September), when the lull in agricultural work freed many to attend semiannual refresher instruction. These meetings were followed by regular popular lectures during the festival seasons that soon followed. Thus, while rabbis constituted a distinct class within the community, their efforts were oriented toward making as much of the community as possible members of a learned and religious elite. The harmonious relations that obtained with but few interruptions over the centuries between the Sāsānian rulers and their Jewish subjects gave the Jewish population the air of a quasi-state, which the Jewish leadership frequently extolled as superior to the Jewish community of Palestine.

The dissemination of the Palestinian Talmud probably stimulated the Babylonians to follow suit by collecting and arranging the records of study and decisions of their own academies and courts. The Babylonian Talmud, which apparently underwent several stages of redaction (c. 500–650) on the basis of the proto-Talmuds—the early collections of commentaries on the Mishna used in the academies—accordingly became the standard of reference for judicial precedent and theological doctrine for all of Babylonian Jewry and all those communities under its influence. Some scholars have postulated a group of anonymous editors of these earlier materials, calling them stammaim (“anonymous ones”). As had been the case with the Mishna, the redaction of the Babylonian Talmud was later designated by authorities as marking the end of a period in Jewish history. The scholars who added the finishing stylistic touches, known as savoraʾim (“explicators”), were classified as a transitional stage between the amoraim and the geonim.

The enduring vigour of Jewish faith during these centuries is graphically demonstrated by the missionary activity of Jews throughout the ancient Middle East, especially in the Arabian Peninsula. Proud Jewish tribes living in close proximity to each other in the vicinity of Yathrib (later Medina, Muhammad’s home city) engaged in agriculture and commerce and proclaimed the superiority of their monotheistic ethos and eschatology. In Yemen (southwestern Arabia) the last of the Ḥimyarite rulers (reigned from c. 2nd century ce), Dhu Nuwas, proclaimed himself a Jew and finally suffered defeat in approximately 525 as a consequence of Christian influence on the Abyssinian armies. Jewish missionaries, however, continued to compete with Christian missionaries and thus helped to lay the groundwork for the birth of an indigenous Arabic monotheism—Islam—that was to alter the course of world history.

Triumph of the Babylonian rabbinate

The lightning conquests in the Middle East, North Africa, and the Iberian Peninsula by the armies of Islam (7th–8th century) created a political framework for the basically uniform (i.e., Babylonian) character of medieval Judaism. As a “people of the Book” (i.e., of the Bible), the Jews were permitted by the Muslims to live under the same autonomous structure that had developed under Arsacid and Sāsānian rule. The heads of the two principal academies were now formally recognized by the exilarch, and through him by the Muslim caliphs (the civil and religious heads of the Muslim state), as the official arbiters of all questions of religious law and as the religious heads of all Jewish communities that came under Muslim sway. Known as geonim (plural of gaon, “excellency”), they conducted high courts manned by scholars of graded ranks, and they received financial support from Jewish communities assigned to them by the exilarch. Religious questions and contributions were solicited from all Jewish communities, and these, along with formal gaonic replies (responsa), were regularly publicized at the semiannual kalla convocations. Under the strong leadership of Yehudai, gaon of Sura (presided 760–763), the Babylonian rabbinate made vigorous efforts to replace Palestinian usage wherever it was still in vogue—including the study of Palestinian amoraic legal literature—with Babylonian practice and texts, thus making the Babylonian Talmud the unrivalled standard of Jewish norms. The campaign’s success is indicated by the usage of the term Talmud, which, when unqualified, has ever since meant the Babylonian Talmud. Indeed, even in Palestine the Babylonian corpus displaced its older rival and caused the study of Palestinian Talmudic literature to be confined to circles of legal specialists.

Anti-rabbinic reactions

The firm—and occasionally oppressive—tactics of exilarchs and geonim generated anti-rabbinic reactions in the form of sectarian and messianic revolts, especially in outlying areas where enforcement was difficult. Inspired in part by ancient Palestinian sectarian doctrines and in part by Muslim usage, the sects were by and large quickly and forcefully suppressed. In the 8th century, according to the traditional Rabbinite account, Anan ben David, a disaffected member of the exilarchic family, founded a dissident group, the Ananites, later known as the Karaites (Scripturalists). The exact relationship between the followers of Anan and the later Karaites, however, remains unclear. The term itself first appeared in the 9th century, when various dissident groups coalesced and ultimately adopted Anan as their founder, though they rejected several of his teachings. The new group advocated a threefold program of rejection of rabbinic law as a human fabrication and therefore as an unwarranted, unauthoritative addition to Scripture; a return to Palestine to hasten the messianic redemption; and a reexamination of Scripture to retrieve authentic law and doctrine. Under the leadership of Daniel al-Qumisi (c. 850?), a Karaite settlement prospered in the Holy Land, from which it spread as far as northwestern Africa and Christian Spain. A barrage of Karaite treatises presenting new views of scriptural exegesis stimulated renewed study of the Bible and the Hebrew language in Rabbinite circles as well. The most momentous consequence of these new studies was the invention of several systems of vocalization for the text of the Hebrew Bible in Babylonia and Tiberias in the 9th and 10th centuries. The annotation of the Masoretic (traditional, or authorized) text of the Bible with vocalic, musical, and grammatical accents in the Tiberian schools of the 10th-century scholars Ben Naftali and Ben Asher fixed the Masoretic text permanently and, through it, the morphology of the Hebrew language for Karaites as well as Rabbinites.

In the face of sectarian challenges, the geonim intensified their efforts against any deviation from Rabbinite norms. They began to issue handbooks of Jewish law that set forth in concise and unequivocal terms the standards for correct practice. A number of these codes, notably the Halakhot gedolot (“Great Laws”), Siddur Rav Amram Gaon (“The Prayer Book of Rav Amram Gaon”; on liturgical practice), and Sheʾeltot (“Disquisitions”) by Aḥa of Shabḥa (c. 680–c. 752), attained authoritative status in local schools and further unified medieval Judaism.

The geonim, however, were powerless to halt several social developments in the 9th century that progressively undermined their hold even on Rabbinite communities. A renaissance of Greek philosophy and sciences in Arabic translation, coupled with the progressive urbanization of the upper classes of all religious and ethnic groups in the centres of political, commercial, and cultural activity, generated a new intelligentsia that cut across religious and ethnic lines. Widespread skepticism concerning basic doctrines of faith such as creation, revelation, and retribution was most poignantly represented by latitudinarianism (the tendency to be flexible and tolerant about deviations from orthodox beliefs and doctrines) and by antinomian gnostic groups that denied divine providence and omniscience (see antinomianism). Ḥiwi al-Balkhī, a 9th-century skeptical Jewish pamphleteer, scandalized the faithful by openly attacking the morality of Scripture and by issuing for schools an expurgated edition of the Bible that omitted “offensive” material (e.g., alleged stories of God acting dishonestly). A mystifying Hebrew tract titled Sefer yetzira (“Book of Creation”) posited in terse and enigmatic epigrams a novel theory of creation that betrayed Neoplatonic influence. Karaites joined philosophically oriented intellectuals in heaping scorn on popular Rabbinite customs that smacked of superstition and, above all, on Talmudic homilies that referred to God in anthropomorphic terms.

Gaonic difficulties were compounded by the rise in North Africa and Spain of populous and wealthy Jewish communities that, thanks to the development of their own local schools and talent, ignored the Babylonian academies or favoured one over the other with religious queries and, in consequence, with financial contributions. To the delight of dissidents and the chagrin of the faithful, competition between the Babylonian academies turned to internecine hostility. Occasional revolts against exilarchic taxation and administration in outlying areas of Persia had to be quelled with armed force. The Palestinian Rabbinites had revived their own academies, and their presidents now not only appealed for support in other Diaspora lands but challenged the authority of the Babylonians to serve as final arbiters on matters of public import, such as the regulation of the calendar. By 900 the Rabbinite community of Babylonia was in a state of chaos and dissolution.

The gaonate of Saʿadia ben Joseph

In a bold effort to restore discipline and respect for the gaonate, the exilarch David ben Zakkai (916/917–940) bypassed the families from whom the geonim had traditionally been selected and in 928 appointed Saʿadia ben Joseph (882–942) to head the academy of Sura. Of Egyptian birth, Saʿadia had gained wide acclaim for his scholarly retorts to Karaites, heretics, and Palestinian Rabbinites. Politically, Saʿadia’s brief presidency was a fiasco and aggravated the chaos by a communal civil war. His gaonate, however, gave an official stamp to his many works, which responded to the ideological challenges to Rabbinism by restating traditional Judaism in intellectually cogent terms. Saʿadia thus became the pioneer of a Judeo-Arabic culture that would blossom fully in Andalusian Spain a century later. His translation of the Bible into Arabic and his Arabic commentaries on Scripture made the rabbinic understanding of the Bible accessible to masses of Jews. His poetic compositions for liturgical use provided the stimulus for the revival of Hebrew poetry. Above all, his rationalist commentary on the puzzling Sefer yetzira and his brilliant treatise on philosophical theology, The Book of Beliefs and Opinions, synthesized the Torah (understood as the divine law in the Five Books of Moses together with the rabbinic understanding of this revelation) and “Greek wisdom” in accordance with the dominant Muslim philosophical school of kalām. His efforts made Judaism philosophically respectable and the study of philosophy a religiously acceptable pursuit.

Far from tightening the gaonic hold over the Jewish communities of the Arabic world, Saʿadia’s works actually provided the wherewithal for ever-greater intellectual and religious self-sufficiency. While economic, political, and military upheavals progressively weakened various institutions in the Middle East, concurrent prosperity and consolidation in the West stimulated the maturation of indigenous leadership in Egypt, Al-Qayrawān (Kairouan; in present-day Tunisia), and Muslim Spain. To be sure, able geonim such as Sherira and his son Hai (939–1038) exercised enormous influence over the Judeo-Arabic world through hundreds of legal responsa issued in the course of their successive terms (968–1038) at Pumbedita. Circumstances beyond anyone’s control, however, were gradually undermining the effectiveness of exilarchate and gaonate. But by 1038, the year of Hai’s death, the consequences of four centuries of gaonic activity had become indelible: the Babylonian Talmud had become the agent of basic Jewish uniformity; the synthesis of philosophy and tradition had become the hallmark of the Jewish intelligentsia; and the Hebrew classics of the past had become the texts of study in Jewish schools everywhere.