If that identification is correct, though, they were, at most, a tiny and beleaguered sect. Manichaeism, despite the best efforts of Mani himself, never managed to capture the loyalty of a Shahanshah, let alone a Caesar. As a result, by the lifetime of Muhammad, the two great empires of the age had forced its adherents into a desperate and bloody retreat. In Iranshahr, the prophet himself had ended up martyred on the personal orders of Shapur’s heir. Meanwhile, the Roman authorities, even prior to Constantine’s conversion, regarded his teachings with the utmost suspicion—as a perfidious Persian attempt to corrupt their “innocent and modest”61 citizens. The Christian empire, naturally enough, had inherited and refined this hostility, so that Manichaeism, by the time of Justinian’s death, had effectively been extirpated from the entire sweep of Constantinople’s dominions. The most bitter and implacable opposition to Mani’s doctrines had come, however, not from monarchs but from the leaders of rival faiths: bishops, mowbeds and rabbis. To them, the upstart prophet’s claims were doubly monstrous. It was not simply that Mani had cast their own scriptures as superseded revelations—although that, of course, was offensive enough. Even more loathsome, in their opinion, was the manner in which he had served as bawd to any number of rival faiths, forever mating and cross-breeding them, until, brought to life out of all the endless miscegenation, there had emerged the deformed hybrid that was his own sinister compound of teachings. Steeled by this perspective, both the Roman and the Persian authorities were confirmed in a fundamental presumption. The blurring and merging of beliefs, such as once had been common across the Fertile Crescent, was an offence that stank to the highest heavens. The no-man’s land that stretched between the various faiths was on no account to be trespassed upon. What the faithful needed, as a synod of Nestorian bishops expressed it in 554, were “high walls, impregnable fortresses, protecting their guardians against danger.”62 Divided though Christians, and Zoroastrians, and Jews might be, yet on one thing they could all agree: the prospect of a second Mani was a horror not to be borne.
War served only to deepen this conviction. Across the mangled provinces of Iranshahr and the New Rome, the horrors of the age saw an increasingly violent and desperate scrabbling by rival communities of monotheists for the patronage of God. Whether it was by Christians lamenting the rape of Jerusalem, or by Zoroastrians mourning the extinguished Fire of the Stallion, or by Jews bewailing the rumours of forced conversions, barricades were being raised, and trenches dug, on an ever more formidable scale. In such a world, where the borders of faith had come to be trammelled and patrolled as never before, what best enabled a religion to thrive was reach, and organisation, and scale: much the same advantages, in short, as made for military muscle. Any sect unable to command such resources was doomed to suffer a lethal rate of attrition.
By the start of the seventh century, monotheism’s triumph throughout the two rival empires was almost total. Of the ancient habits of pagan worship that had once been so universal, only a few scattered outposts still held out. In Khorasan, for instance, all the empire-building efforts of the Zoroastrian priesthood had failed to topple Mihr—that awful and sleepless avenger of injustice—from his mountainous and dawn-illumined throne. In Harran, too, which had long relied on its position midway between Rome and Iranshahr to perpetuate its venerable cult of Sin, the majority of the inhabitants still persisted in defying their nominal lord in Constantinople and refused to worship Christ. Nevertheless, the future for the Lord of the Moon looked bleak. Under Maurice, a particularly officious bishop had been appointed to the city’s see, charged with scouring it clean of demon worship once and for all. Secret pagans in high places had been exposed, put to death, and gibbeted in the high street. For the worshippers of the Moon, then, occupation by Khusrow II’s forces had come in the nick of time. The Persians had been far too preoccupied with their conquest of the world to concern themselves with the cult of Sin. By 629, however, with the conclusion of peace and the evacuation of the Persians from Harran, a restoration to Roman control was imminent. The writing now really did seem to be on the wall for the city’s idols.
Pagans and Manichaeans, Jewish Christians and Christian Jews: persecution had been the common fate of all. There was no secure refuge from the imperial authorities to be found anywhere in the Fertile Crescent, save where it had always been: along its margins. For centuries, whether as a sanctuary or as a place of exile, the immense wilderness to the south of the two great empires had played host to beliefs that elsewhere had faded away, like ink on a crumbling scroll. To cross the frontier and head into the desert was therefore to step back in time. Only in Arabia, beyond the reach of monarch, bishop or mowbed, did the ancient promiscuity of cults endure. That Jews and Christians were to be found among the Arabs was certainly true—but not so that either could be confident of dominating the other. Even in Himyar, where first a Jewish king and then a Christian invader had seized power, neither regime had done much to dispel Arabia’s ancient reputation as a breeding ground for heresy. By posing as the heir of David, Yusuf had indulged in precisely the kind of showmanship fit to appal most rabbis, while in Najran, the name given to the great shrine raised in honour of those martyred for Christ—the Ka’ba—bore unmistakable witness to the relish of the pagan Arabs for reverencing cubes. Nor, indeed, had Himyar ever been securely fire-proofed as a Christian realm. In the last years of Khusrow I’s reign, a Persian-sponsored coup had terminated the Ethiopian occupation, and within a couple of decades Ctesiphon had established direct rule over the kingdom. The merchant from Iranshahr, “adorned with ear-rings, and with a Persian twang to his speech,”63 had become an ever more familiar figure to the Arabs; and with him, in his wake, he had brought the worship of Ohrmazd. One more religion added to all the others in the teeming seedbed.
Meanwhile, far to the north of Himyar, on the margins of the Fertile Crescent—and especially along the margins of Palestine—there was even greater scope for cross-pollination. Nowhere else in the entire Near East had so many varieties and shades of faith survived intact. There were Jews, whose appeal to the Arabs of the desert had been noted long previously by Sozomen; and monks, those unyielding defenders of Chalcedonian orthodoxy; and the Monophysite warriors of the Banu Ghassan. Samaritans too, despite the calamitous failure of their revolt against Justinian, had continued to dash themselves against the rock of Roman power, and then, in the wake of the inevitable defeat and repression that followed, to stream in broken misery out into the neighbouring deserts. By abandoning the Holy Land, they were merely following paths already well-trodden by others: by Ebionites, by Nazoreans, by any number of Christian heretics. Not, it went without saying, that every pattern in the mosaic of belief to be found in northern Arabia was fashioned out of materials that were brought across the Roman frontier. The pagan traditions that had prompted Mundhir to wet al-’Uzza’s altar stones with the blood of four hundred virgins and the Nabataeans to worship the black Ka’ba of Dushara had never—in contrast to those of the Fertile Crescent—suffered active repression. If even the Christians of Najran had preserved, in the name they gave to their great shrine, evidence of their ancestors’ reverence for worshipping rocks, then it suggests that elsewhere too in Arabia, wherever the faiths and customs of outsiders met with those native to the Arabs themselves, the scope existed not merely for conflict but for that ultimate nightmare of the imperial authorities: the cross-breeding of rival beliefs.