Or so he liked to think. In fact, the message conveyed by the militarisation of the frontier was altogether more ambiguous than Justinian might have wished. The rival pretensions of Dara and Nisibis, frowning at each other across the Mesopotamian flat-lands, could easily seem to make a mockery of both. “The nations are like a drop from the bucket, and are accounted as the dust on the scales.”43 So it was written in the Tanakh. The Jews, lacking any empire of their own, treasured a distinctive perspective on international affairs. It reassured them that the great kingdoms of the world, despite all their clamour and posturing, were accounted by God “as less than nothing and emptiness.”44 They knew that the true division of the world was not the one proclaimed by the battlements of Dara, between Roman and barbarian, but something quite else: between those who lived in the manner ordained by the Almighty and those who did not.
Given this, who was to say that the scattering of the Jews far beyond the limits of their ancestral homeland was not all part of the heavenly plan? “By your descendants,” God had told Abraham, “shall all the nations of the earth bless themselves.”45 This assurance had long prompted many Jews to ponder the immense distances that separated them from the Promised Land, and to arrive at a daring conclusion. As one rabbi, back in the time of Constantine, had put it with forthright conviction, “The Holy One, blessed be He, exiled us among the nations in order that converts might swell our ranks.”46 This, it might have been thought, was rather to contradict the emphasis that the Almighty had placed on the significance of Abraham’s bloodline; but it was also to assert that “Jewishness,” in the final reckoning, was determined less by blood than by obedience to the demands of the Torah. Accept that, and the Jews did certainly appear well placed to reshape the world. Mesopotamia was certainly far from being their only home away from home. Few were the points of the compass where they were not to be found. They had become, in a sense, more truly universal than any empire. Rather like the Greeks, they ranked not merely as a people but as the agents of a culture, of an entire way of understanding, interpreting and refashioning the world. The awesome power of their ferociously demanding God, the staggering antiquity of their laws, and the glamour of what seemed to many less a faith than a private members’ club: all had combined to make the Jews objects of rare fascination to those among whom they lived. Unsurprisingly, then, there was a venerable tradition of their admirers becoming “proselytes”—“which is to say, people who have been made into Jews.”47 In Rome, the imperial authorities had been fretting about such conversions since the time of the republic. A whole succession of emperors had sought to regulate what they saw as a palpable and growing menace. A century and a half before Constantine, the circumcision of converts had been declared equivalent to castration: a crime that would see the perpetrator exiled to a desert island. Faint consolation to the Jews themselves though it might have been, there was testimony here to their faith’s profound appeal. The superstitions of conquered people were rarely honoured by the Roman elite with such hostility. The resentment and indignation of the rulers of the world were nothing if not a form of tribute.
But how, precisely, was a Jew to be defined? It was to answer this question, of course, that the rabbis of Mesopotamia, back in the time of Ardashir, had founded the famous yeshivas of Sura and Pumpedita, and embarked upon the great project of research that would culminate in their transcription of the Talmud. Mesopotamia, however, was not the world. No matter what the rabbis themselves might care to think, most Jews were largely oblivious to their existence. For the first few centuries after the founding of the yeshivas, the scholars who taught in them were more interested in ensuring that they were listened to in their own backyard than in establishing a global voice. Across the eastern reaches of Iranshahr itself, in much of the Roman world, and in the deserts and mountains that lay beyond the reach of both empires, rabbis were signally lacking. Authority lay instead with the leaders of what had come to be known as “synagogues.” These were communal meeting places where the Torah was studied and debated, and where Jewishness—Ioudaismos, in Greek—was rarely a given. Different communities, and different individuals, tended to define it much as they pleased. Often, it might seem as though the definition of a Jew was simply someone who described himself as such. Consequently, the boundary that demarcated Jews from non-Jews—“Gentiles,” as they were called—was never entirely stable. One Jew might take the high road that led to Persepolis and there, on the lintels of that Zoroastrian holy place, carve a summons to the people of Iranshahr to join his faith;48 another, panic-stricken at the thought of falling for the insidious attractions of foreign women, and thereby jeopardising the purity of Abraham’s bloodline, might try and avoid so much as stealing a glance at a Gentile. Even the rabbis, despite their burning ambition to distinguish themselves and their people as rigidly as possible from the world beyond, found it impossible to agree on who precisely qualified as a Jew. Some argued that proselytes were fully Jewish. Others maintained that they were “as injurious as sores.”49 Neither side found it possible to establish a definitive answer. They had no option, so it seemed to the rabbis, save to agree to disagree.b
Except that there did exist another option. Long before the founding of the great rabbinical schools of Mesopotamia, in an era so distant that even the title of “rabbi” itself had only tentatively begun to be employed, a small group of Jews had made a spectacular announcement: that a notorious troublemaker by the name of Jesus, recently crucified and supposedly risen from the dead, was none other than the “Christ.” More than that, indeed—that this same Jesus was also, in some mysterious manner, the Son of God Himself. These Christians—as they soon came to be known—had not initially thought of themselves as any the less Jewish for holding these startling beliefs. Nor had it ever crossed the minds of most of them that the Torah, that incomparable framework for living granted to His Chosen People by the Almighty Himself, might conceivably have been rendered redundant. Yet there were some, pushing the implications of their new beliefs to radical limits, who had soon arrived at precisely such a conclusion.
A few decades on from Jesus’s crucifixion, a group of Christians in Asia Minor received a letter that positively seethed with scandalous notions. Its author, a one-time student of the Torah called Paul, was the most spectacular rebel that the famously prescriptive Jewish educational system had ever bred. “There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus.”50 In this revolutionary proclamation, Paul deftly cut what had always been, for Jewish scholars, the ultimate Gordian knot. No need, so Paul announced with a flourish, to pick at the problem one moment more. Whereas once it had been the Torah which gave to the Chosen People their roadmap to the purposes of God, now, with the coming of Christ, the need for such a Law was gone. The whole question of what it was that made for a Jew had been dissolved into irrelevance. No longer was there any obligation to follow the Torah’s rulings, to be bound by its strictures, to attend to all its endless finger-wagging: “Now that faith has come, we are no longer under a custodian; for in Christ Jesus you are all sons of God, through faith.”51 The Gentiles too, so Paul had concluded, were heirs to the promise made by God to Abraham. No longer were the Chosen People defined by a lineage of blood, or by adherence to a law, but by the knowledge and love of Christ. Nations everywhere, in short, might now be ranked as the children of Abraham. All it needed was for the entire world to end up Christian.