An apocryphal piece of academic lore recounts the story of a graduate seminar at Columbia in which the late Yosef Yerushalmi asked his students to name the single most important event in Jewish history. "The destruction of the second Temple?" one hazards. "No!" Yerushalmi thunders; "you're thinking like yeshiva buchers." "The founding of the state of Israel?" "No!" he bellows; "you're thinking like Zionists. Think like historians!" The answer he seeks: the imposition of the land tax after the Islamic conquests. An answer more pedestrian, even boring, his students think, cannot be imagined; they are perplexed, but no one dares object. He explains: the land tax brought Jews to cities, changing Jewish history forever.
How did what we now call the Babylonian Talmud, a collection of scholastic texts studied in small disciple circles in tiny farming towns on the Euphrates, become the canonical text central to Jewish law from Jerusalem to Paris, Copenhagen to San'a, Brooklyn to Los Angeles? To the extent that the answer lies in the medieval period (and not in movable type, offset printing, mass literacy, or Dial-a-Daf), it has everything to do with migration from the Iraqi countryside—and, a bit later, with mass migration from Iraq itself.
Few would argue with the idea that urbanization during the early Islamic period permanently altered the trajectory of Jewish history. True, the Babylonian Talmud contains more rulings on crafts, trade, and town life than its entirely rural Palestinian counterpart. But the Islamic conquests turned the occasional abandonment of farming into a veritable collective flight to the city—and not just for Jews.
While the fledgling Islamic government's land tax (kharaj) was not entirely new—in Iraq, it was modeled on Sasanian precedents— peasants did not merely render the old tax to new masters. The early Islamic state increased the rural tax burden, extended it over new kinds of produce, and devised more efficient ways of collecting it. Since villages had to pay the kharaj collectively, when people left for the city, they increased the liability of those they left behind and, in turn, increased pressure for those remaining in villages to leave, too. The 'Abbasids (750–1258) mitigated the situation somewhat by introducing payment in kind (rather than cash) to the district surrounding Baghdad in order to provision the growing city; peasants could then avoid borrowing money at ruinous rates of interest to pay the state. But the burden of subsistence farming still spurred ever greater numbers of people to abandon agriculture for cities.
After 762, the main target of migration was the newly founded 'Abbasid capital at Baghdad, which brought the center of the civilized world close to some of the world's major Jewish settlements. The exilarch's seat had been the Sasanid winter capital Mahoza (or Medinata; in Arabic, al-Mada'in), a group of cities connected by pontoon bridges over the Tigris; for better access to the 'Abbasid court, he now moved 32 kilometers north to Baghdad. A generation later, the rabbinic elite already understood that rural flight was changing Jews' economic prospects. Talmudic precedent had required debts on the estates of the deceased to be collected only from real estate, but declining land ownership among Jews had rendered the old ruling unworkable. In 786–87, the gaon of Sura and the exilarch ruled that those debts could now be collected on movable property instead. This momentous change in Jewish law is corroborated by a broader pattern in rabbinic literature: though some gaonic responsa still addressed queries from peasants, the vast majority now dealt with questions from urban settings.
But for more than a century after Baghdad's founding, the Babylonian yeshivot resisted the move to the capital on the Tigris, remaining at Sura and Pumbedita on the Euphrates. This may have been because paying court was perceived as the exilarch's task. Or perhaps turmoil in the capital kept the geonim from committing their fortunes to Baghdad: in 836, locked in conflict with his Turkish army regiment, the caliph al-Mu'tasim moved his court 125 kilometers north to Sa-marra', where it stayed until 892. The yeshivot stayed put, at least for the moment, and the population of Sura and its surroundings remained primarily Jewish, at least according to the Muslim theologian Ibn Qutayba (828–89). Even those who had remained in the countryside were now better connected than ever with the center: Arab geographers report a regular mail route between Pumbedita and Baghdad, a distance of about 62 kilometers.
Pumbedita was the first to move to the capital. A responsum reports the date as 889–90, though it is easier to imagine the move having taken place after the 'Abbasid court returned to Baghdad. Sura arrived in the capital a bit later, likely in the early tenth century. The last report of Sura as a Jewish city comes from a biographical account of Ibn al-Qifti (1172–1248) in which a court physician named Sinan ibn Thabit sought permission from the caliph al-Muqtadir (908–32) to treat those suffering from plague in Sura, "and they are Jews."
The move to Baghdad changed the geonim and their work. Over the tenth century, the yeshivot metamorphosed into cosmopolitan and outward-looking institutions headed by polymath geonim educated outside their confines, such as Se'adya ben Yosef al-Fayyumi (d. 942), Shemu'el ben Hofni (d. 1013), and Hayya bar Sherira (d. 1038). The difference, one might say, was comparable to that between maintaining a seminary in Breslau (or today's Cincinnati?) and one in New York or Los Angeles.
As the Iraqi population urbanized and the 'Abbasids came to rule one of the largest empires in history, Baghdad grew into the most important city in the Near East. With urban growth came vastly expanded geographic mobility. In the latter half of the ninth century, Baghdadi-Jewish traders speaking a staggering number of languages (Arabic, Persian, Greek, and various Slavic and romance dialects) reached western and eastern Europe, Constantinople, the Caspian Sea, India, and China. The routes they followed were standard for their time, with the notable exception of the overland route to China via the Khazar kingdom, which seems to have been their own invention. Gaonic responsa corroborate Jewish traffic in slaves, textiles, and spices.
The result of growing international commerce was wealth at home. Some traders amassed the capital to sell luxury goods to rulers and then served the court in other capacities or moved into banking. Several Jewish mercantile dynasties became 'Abbasid courtiers and administrators while playing an ever greater role in communal politics and lending their support to rival factions of yeshivah leaders. The 'Abbasid court even became enmeshed in Jewish factional warfare, as when a court banker (jahbadh) named Yosef b. Pinhas (d. c. 920) backed a gaon of Pumbedita, Kohen Sedeq (926–35), against an exilarch named 'Uqba, who had attempted to take over his rashut (right to collect taxes) in Khurasan. Together with his son-in-law Netira (d. 916), himself the descendant of an 'Abbasid jahbadh, Yosef b. Pinh.as convinced the court in Baghdad to take his side, forcing 'Uqba into exile in distant Kirmanshah.
The population of Baghdad is likely to have exceeded one million by the tenth century, numbers the world hadn't seen since ancient Rome and would not see again until late eighteenth-century London. Eyewitnesses boasted of the huge number of markets. Booksellers (who both sold and copied books) numbered as many as one hundred, a ratio of outlets for fine literature per capita that rivals that of Seattle, currently America's best-read city. In retrospect it is hard to explain how all those mouths could be fed and watered. And indeed, the city's prosperity would not last long.
No sooner had the population and wealth of Baghdad peaked than political chaos and economic decline stunted its ascendancy. Large slabs of the 'Abbasid realm fell away, most significantly, Ifriqiya (central North Africa, centered on Qayrawan) in 909, and the wealthy province of Egypt in 969, both conquered by the upstart Shi'i Fatimid caliphs, who then pressed eastward and took Palestine and Syria as well. Baghdad itself was in peril. With the ascent of the Fatimids, the civilized world shifted westward toward the hubs of the Indian Ocean and Mediterranean trades: Fustat and the Fatimid capital just north of it, Cairo. The geographer al-Maqdisi (d. c. 990) assessed the situation this way: "[Egypt's] metropole has now become the greatest glory of the Muslims; Baghdad has been superseded until Judgment Day." Anyone with a skill to ply—merchants, government bureaucrats, religious leaders; in short, anyone literate— read the writing on the wall and left the 'Abbasid heartland for the Fatimid Mediterranean.
Flight from Iraq had a marked effect on the world of the yeshivot. Even that archpropagandist on behalf of the continuity of rabbinic Judaism, Avraham ibn Dawud of Toledo (d. 1180), admitted that the period between 960 and 990 found the Babylonian geonim in deep crisis: "the income of the yeshivot," he wrote, "which had come from Iberia, the Maghrib, Ifriqiya, Egypt, and the land of Israel, was discontinued." The admission is significant given his otherwise outrageous claims on behalf of the superiority of Babylonian rabbinic tradition.
Grim though things looked for the academies' income, westward migration actually helped the cause of gaonic continuity by spreading eastern Jews and their loyalty to the Babylonian center well beyond the confines of Iraq. The Jewish communities in Fustat, Qayrawan, Palermo, and numerous towns in Syria-Palestine were by now teeming with Iraqis, and their arrival made it easier for the Babylonian geonim to win supporters abroad.
Not that the geonim amassed and retained supporters without a struggle. No one could take for granted that people of eastern origin would offer fealty to Baghdad. Most cities hosted three Jewish communities—Iraqi Rabbanite, Syro-Palestinian Rabbanite, and Qaraite—and Jews offered and withdrew their loyalties at will. In one memorable case c. 1030, a number of Palestinian Rabbanites threatened to defect to the Iraqi and Qaraite congregations merely because they disliked their rabbi's high-handed attitude.
Gaonic letters also attest to the inherently political nature of the job. The presence in Mediterranean cities of long-distance traders with ties to Baghdad, including some of the great Iraqi and Iranian merchant houses, made it easier for the geonim to demand and receive donations and for their responsa to arrive in far-off places. The geonim took note. Luminaries such as Shemu'el ben Hofni and Hayya bar Sherira maintained lifelong alliances with traders who helped them raise funds in Egypt and Ifriqiya (among them two Qaraite families).
But westward migration also resulted in significant ruptures within Iraq and protracted conflict with the Palestinian-rite congregations, sometimes on their own turf. Sura was forced to close its doors for four decades (943–87), as Iraqi immigrants established their own congregations in parts of Palestine where Jews had always followed the Palestinian rite, including Banyas and possibly even Tiberias, the very seat of the Palestinian yeshiva until c. 960. In the early 1030s, an Iraqi faction attempted to establish formal jurisdiction over Iraqi-rite followers in Palestine—until then, the province of the gaon of Jerusalem—by petitioning the Fatimid caliph for recognition of their leader. The Jerusalem gaon Shelomo ben Yehudah al-Fasi (d. 1051), a brilliant politician who outmaneuvered a succession of rivals during his quarter-century in office, blocked the attempt with a counter-petition to the Fatimid caliph, but he could not fight demography: his successor in the gaonate of Jerusalem, Dani'el ben 'Azarya (d. 1062), was an Iraqi of exilarchal descent. Around 1040, both Babylonian yeshivot had closed down and would not reopen until the second half of the twelfth century; members of exilarchal families and gaonic contenders sought and found their fortunes elsewhere. Crisis in the east produced a burgeoning political life in the west.
Accounting for Babylonian rabbinic hegemony is then more complex than simply tracking the reception and transmission of the Babylonian Talmud and gaonic responsa. I began to fathom the complexity of the problem during a conversation I had on a curbside in Paris with Judith Olszowy-Schlanger as we waited to pick up her children from school. The physical features of masoretic manuscript fragments, she said, could confirm that the earliest Tiberian masoretic texts from the late ninth and tenth centuries already show traces of Babylonian influence; she and others have found the same to be true of the earliest Qaraite works. Those findings underscore the significance of westward migration from Iraq: even the very people fighting the Iraqis on behalf of Palestinian independence and hegemony—Qaraites included—had themselves already been shaped by the various Babylonian constructions of Judaism.
Polemicists such as Ibn Dawud and Pirqoy ben Baboy would have us believe that the Babylonian tradition conquered the west because it was inherently superior to the others. But to believe them is to judge history by its outcome. The demographic factor suggests that it was neither the strength of Jewish law nor the authority of the Babylonian geonim alone that led to the pervasive (if varied) influence of Iraqi traditions on Judaism, but a host of factors that also reshaped the wider Middle East and Mediterranean.