The Middle East Became Christian Slowly, Then All at Once

There was no year the Middle East "became Christian." There were three conquests, moving at three different speeds, and the mistake most popular accounts make is to run them together into a single story that starts with Jesus and ends with Constantine holding a cross over a converted empire. It did not happen that way. Christianity took the cities first, as a minority movement, for roughly two hundred and fifty years. It took the law next, in a burst of imperial legislation stretched across a single century. It took the countryside last, unevenly, and in a few stubborn pockets not at all. By the time the Arab armies rode out of the Hijaz in the 630s, the region we now call the Middle East had been Christian, as a matter of state religion and majority practice in most of its cities, for roughly three hundred years — longer than the United States has existed. That fact does not sit comfortably in most people's heads, because the region's later history buried it. This essay is about recovering the tempo, and about a harder claim underneath it: the Middle East was not on the edge of the Christian world before Islam. It was the middle of it.

The cities, first, and slowly

For roughly the first two and a half centuries after the crucifixion, Christianity was an urban minority religion speaking Greek. It grew inside the cities of the eastern Mediterranean — Antioch, Alexandria, Ephesus, Corinth, eventually Rome — because that is where the roads, the synagogues, the marketplaces, and the literate class that could read a letter from Paul all were. Eusebius of Caesarea, writing his Ecclesiastical History in the early fourth century, traces this expansion city by city and bishop by bishop, and even allowing for his own bias toward triumphant narrative, the pattern he describes — a network of urban congregations linked by letters and travelling teachers, growing inside but never coextensive with the empire's cities — matches what modern historians reconstruct from other evidence.¹

How big was that minority, and how fast did it grow? This is genuinely contested, and the numbers you sometimes see stated as fact are models, not counts. Rodney Stark, working from the sociology of new religious movements, proposed that Christianity grew at a roughly constant rate of about forty percent per decade from a tiny base — a curve that would put Christians at well under one percent of the empire's population through most of the second century, climbing past ten percent only in the second half of the third, and approaching something like half the population by the time Constantine legalized the faith in 313.² Stark's model is elegant and has been influential, and it is also a projection built on assumptions about starting size and constant growth rate that no ancient census can confirm or refute; historians of the period, including Ramsay MacMullen, have pushed back on both the smoothness of the curve and the confidence of the endpoint. What the evidence from inscriptions, papyri, and church councils does support, without needing a growth model, is the shape of the thing: a minority movement, concentrated in cities, that was still a minority — probably a substantial one in a few places, a slight one almost everywhere else — on the eve of Constantine.³

It was also, for most of that period, a legally exposed minority. Christians were not perpetually or uniformly persecuted — the empire's default posture toward the cult for long stretches was indifference rather than hunting — but persecution was real, periodic, and occasionally systematic, culminating in Diocletian's empire-wide edicts against Christians beginning in 303. None of that stopped the cities from filling up with Christian communities, bishops, and buildings; it just meant that Christianity was still, structurally, an association operating without the state's blessing and sometimes against its will. That is the condition that changed, abruptly by the standard of the previous two hundred and fifty years, in 313.

Then the law, in a single century

The Edict of Milan in 313, issued jointly by Constantine and Licinius, did not make Christianity the state religion. It made Christianity legal, restored confiscated property to Christian communities, and put it on the same footing as any other cult in the empire's toleration of religions. That is a smaller step than the one people usually credit it with, and a large one anyway: for the first time, a Christian bishop could hold property, meet openly, and appeal to the emperor rather than merely evade him.

What followed moved fast by the standard of the previous three centuries. In 325 Constantine summoned bishops from across the empire to Nicaea, a city in Asia Minor a short ride from his new capital, to settle the dispute over Arius's teaching about the nature of Christ — the first attempt at a single, empire-wide doctrinal formula, backed for the first time by imperial convening power and imperial exile for those who refused to sign it. In 380 the emperor Theodosius I issued the Edict of Thessalonica, which went further than Constantine ever had: it named the Christianity professed by the bishops of Rome and Alexandria, in the Nicene formula, as the religion the empire's subjects were to hold, and it used language treating deviation from it as a matter for imperial correction, not merely private error.⁴ Through the early fifth century, the compilers of what became the Theodosian Code assembled and reissued a long run of legislation narrowing the legal space available to traditional cult: restrictions on sacrifice, on temple endowments, on public festivals, tightening book by book across the code's sixteenth book in particular.⁵ The process did not stop there. In 529 the emperor Justinian closed the Neoplatonic school at Athens — the last public institution teaching philosophy in direct, unbroken descent from the pagan schools of the classical city — and its remaining teachers reportedly left for the Persian court.⁶ Two hundred and sixteen years separate Milan from Justinian's closure of the Academy. That is the entire span in which Christianity moved from a tolerated minority cult to the enforced law of the eastern Mediterranean.

Two hundred and sixteen years separate Milan from Justinian's closure of the Academy — the entire span in which Christianity moved from a tolerated minority cult to the enforced law of the eastern Mediterranean.

It is worth being precise about what "the law" accomplished and what it did not. Legislation can close a temple's public sacrifices; it cannot, by itself, empty a village's private shrine or change what a farmer three days from the nearest bishop actually did at planting time. The gap between what the Theodosian Code demanded and what happened in the provinces it governed is the subject of the next section, and it is a large gap. But the legal transformation itself is not in doubt, and its speed is worth sitting with: an empire that had periodically executed Christians in living memory of men who attended the Council of Nicaea was, within one further century, closing the philosophical schools of its own classical tradition in the name of the faith it had once outlawed.

The countryside, last, and never completely

Ramsay MacMullen's study of how the empire actually Christianized argues, against any picture of smooth, empire-wide conversion, that the process was radically uneven by geography and by class: cities ahead of countryside by generations, the literate and the connected ahead of the rural poor by longer than that, and whole regions where the old cults simply persisted under a thinning veneer of official Christian law long after the edicts said they should have stopped.⁷ Peter Brown's work on the period gives the clearest picture of why: rural religion in late antiquity ran on the same infrastructure as everything else in the countryside — the local shrine, the seasonal festival, the healer, the holy man riding circuit — and that infrastructure did not reorganize itself the moment a law was posted in the provincial capital. It took bishops, monks, and later holy men physically colonizing the countryside, founding rural churches and monasteries, converting local shrines into Christian sites or displacing them by force or persuasion, over generations, to do what an edict alone could not.⁸

The clearest single case of rural persistence is Harran, a city in upper Mesopotamia (in modern southeastern Turkey) whose inhabitants maintained an astral cult — worship organized around the moon god and the visible planets — not just through the Christianizing fourth and fifth centuries but through the Arab conquest of the seventh and well into the Abbasid period of the eighth and ninth. Harran's pagans survived long enough to negotiate, under Islamic rule, a legal status as a protected "people of the book" by identifying themselves with the Quranic Sabians — a maneuver of self-preservation that only makes sense if their astral religion was still a living, organized cult centuries after Theodosius had outlawed sacrifice and centuries after the conquest that is the subject of the next essay in this sequence.⁹ Harran is the exception that proves how uneven the timeline was: not every rural pocket held out for five hundred years, but enough did, in enough places, that no honest account of "the Christian Middle East" can describe it as complete.

There is a second, larger qualification that the phrase "the Middle East became Christian" tends to erase entirely: the Roman Middle East was never the whole Middle East. East of the Euphrates lay the Sasanian Persian Empire, a Zoroastrian state with its own state cult and its own fire temples, and Sasanian Persia held large, organized, and often persecuted Christian and Jewish minorities of its own — Christian communities that grew up largely outside Roman jurisdiction, worshipped in Syriac rather than Greek, and after the Council of Ephesus in 431 increasingly organized themselves as a separate church, the Church of the East, distinct from and sometimes at doctrinal war with the imperial church to their west.¹⁰ When this essay says "the Middle East was Christian for three centuries," it means the Roman half — Anatolia, Syria, Palestine, Egypt — where Christianity held the force of law. Persia was never that. Getting this distinction wrong is the easiest way to overstate the case, and the case is strong enough without overstating it.

The heartland nobody remembers

Here is the fact that later history makes hardest to hold onto: on the eve of the Arab conquests, the Middle East was not a frontier of Christendom. It was Christendom's center of gravity, doctrinally, institutionally, and linguistically, in a way that Rome and the Latin West, for all their later dominance of the story, were not.

Every early ecumenical council — the gatherings that actually defined what "orthodox" Christian doctrine meant — sat on Middle Eastern or Anatolian soil. Nicaea in 325 and Constantinople in 381 hammered out the creed still recited in most churches today. Ephesus in 431 settled (and, in the process, split) the question of how to describe Christ's divine and human natures together. Chalcedon in 451, on the Asian shore across from Constantinople, went further still and produced a formula that a large fraction of eastern Christians — the churches that became the Coptic Church in Egypt, the Syriac Orthodox Church in Syria and Mesopotamia, and the Armenian Church — rejected outright, judging it to compromise the unity of Christ's nature. Historians usually call these dissenting churches Miaphysite, from their insistence on a single united nature in Christ, against the "two natures" Chalcedonian formula that the imperial church in Constantinople enforced as orthodoxy. Not one of the four councils met in Italy. Not one used Latin as its working language. The theology that later Latin Christendom would inherit, argue over, and eventually claim as its own patrimony was forged in Bithynia, Cappadocia, and the Bosphorus by bishops who read and argued in Greek.

The great sees of the early church make the same point from a different angle. Rome mattered, and its bishop's claim to a special authority traced to Peter would eventually reshape the whole of western Christianity. But in the fourth and fifth centuries, the sees whose bishops actually set the theological agenda, ran the great catechetical schools, and fought each other over the nature of Christ in council after council were Alexandria, Antioch, Jerusalem, and Constantinople — all four of them eastern Mediterranean cities, three of them (Alexandria, Antioch, Jerusalem) inside what we would now call the Middle East. The theological languages of this world were Greek in the cities and imperial administration, Syriac across upper Mesopotamia and much of Roman Syria, and Coptic in Egypt outside the Hellenized cities, with Armenian and Ge'ez carrying Christian literature further east and south still. Monasticism, the institution that would define western Christian religious life for a thousand years, was not a Latin invention adapted eastward; it was invented in Egypt by figures like Antony and organized into communities by Pachomius, and independently elaborated in the Syrian desert, before the practice migrated west and north into a Latin world that received it as an import.¹¹ Robert Louis Wilken's account of Christianity's first thousand years makes exactly this point at scale: read the story from Alexandria, Antioch, and Edessa rather than from Rome, and the "rise of Christianity" looks like an eastern Mediterranean and Near Eastern phenomenon that the Latin West joined, not the other way around.¹²

The theology that later Latin Christendom would inherit and claim as its own patrimony was forged in Bithynia, Cappadocia, and the Bosphorus by bishops who read and argued in Greek.

None of this is a minor correction to the record. It means that when the Arab armies took Damascus, Jerusalem, Alexandria, and eventually Ctesiphon in the two decades after 634, they were not absorbing a periphery of the Christian world into a new religious order. They were taking Christianity's own heartland — the cities that had produced its councils, its creeds, its monastic movement, and most of its early theological literature — and inheriting a Christian majority population that would take centuries, not years, to become a Muslim one, the subject this essay's sequel takes up directly.

A heartland that was never one thing

The honest final complication is that "the Christian Middle East" was never a single, unified church even at its legal high point, and that internal fracture is not incidental to what came after — it shaped it. Chalcedon in 451 did not settle the question of Christ's nature; it split the eastern churches into Chalcedonian communities loyal to Constantinople's formula and Miaphysite communities that rejected it, a division that hardened over the following century into separate hierarchies, separate liturgies, and, in Egypt and Syria especially, a Miaphysite majority alienated from an imperial church increasingly identified with Constantinople's tax collectors and garrisons rather than with the theology in the pews. East of the Roman frontier, the Church of the East in Persia had organized itself as a third, distinct communion, out of both Roman jurisdiction and Roman doctrinal controversy, closer in some respects to the theology Ephesus had condemned in 431 than to either Chalcedonian or Miaphysite Christianity.¹⁰ A Byzantine tax official arriving in Alexandria or Antioch in the 620s was not visiting a uniform Christian population loyal to Constantinople. He was visiting a Miaphysite majority that had spent two centuries watching an emperor five hundred miles away enforce a Christology it had already rejected — which is one reason, among several genuinely contested ones, that some of these populations offered the Arab conquerors of the 630s no organized religious resistance at all.

That fragmentation is the essay this one hands off to. The question of how fast, and by what mechanism, the Christian majority of Egypt, Syria, and Iraq actually became a Muslim minority-turned-majority — a process that, as the following essay argues, took centuries rather than years, driven by tax structure and social status more than by the sword — cannot be understood without first holding onto what this essay has tried to establish: that the Christianity the Arab armies inherited in 634 was not young, was not marginal, and was not one thing. It was three centuries deep as the law of the land, older still as a lived urban majority in many of its cities, doctrinally fractured along lines that predated the conquest by two hundred years, and it occupied, by any honest reckoning of councils, sees, and theological languages, the actual center of the Christian world. The empire that would later be called Byzantine, ruling from Constantinople, was the periphery of that world in every sense except the military and administrative one. The Middle East was not converted to Christianity from outside. It produced Christianity's creeds, and then, slowly, unevenly, and never completely, it produced the conquest and conversion that followed — a story with its own tempo, taken up next.