What the Rise of Christianity Can Still Tell Us About Power, Ideology, and Society
A review of "Christendom: The Triumph of a Religion, AD 300-1300" by Peter Heather
How did the small Jewish splinter sect emerge from the backwater Roman province of Palestine and then become the dominant religion of Europe over the course of roughly a millennium?
That’s the question British historian Peter Heather hopes to answer in his magisterial and fascinating new history Christendom: The Triumph of a Religion, AD 300-1300—and answer it he does in convincing fashion. He skewers some traditional narratives that purport to explain Christianity’s rise, offering a compelling argument of his own that the religion’s intimate relationship with the political powers of the day that ultimately determined its destiny. It’s a panoramic view that has much to tell us today about the nature of politics, power, and ideas, how and why some ideas win out while others fall through the cracks of history, and the ways ordinary people and elites alike respond to the ideological and philosophical changes swirling around them.
This seemingly ancient history remains relevant to anyone thinking about ways politics, societies, and people work today in the 21st century.
Heather starts his story with Constantine’s conversion to Christianity in the first years and decades of the fourth century. Contrary to some academic claims that Christians amounted to some ten to twenty percent of the Empire’s population by the time Constantine seized power, Heather argues such assertions are unrealistic in the extreme given the reality that 85 to 90 percent of that population lived in rural areas that didn’t see major Christian conversion campaigns until two centuries later—and two-thirds of urban areas “had no organized Christian community at all.” As a result, Christians probably amounted to something between one and two percent of the Roman citizenry when Constantine publicly declared his allegiance to the religion.
As for Constantine himself, Heather finds no reason to doubt the sincerity of the emperor’s faith. Indeed, Constantine carefully calibrated shifts in the public presentation of his religious beliefs to coincide with major military victories. Given prevalent notions that decisive success on the battlefield indicated “direct, divine support” for the victorious commander, these conquests made it politically safe for Constantine to slowly but surely come out as a Christian. Under the aegis and authority of Empire and emperor, Christianity would evolve from a de-centralized and rigorous sect to a mass religion. Imperially sponsored councils like Nicaea would debate and determine the fundamentals of the faith as it grew over time.
Over the course of the fourth century, Roman landowning elites slowly but surely accommodated themselves to the new imperial religious dispensation. Profound conversion experiences akin to Paul of Tarsus or Augustine of Hippo were not the norm, and Heather argues these vivid accounts are in fact outliers that have distorted our sense of what conversion to Christianity meant for most Roman elites in the years and decades after Constantine. While the Empire didn’t (and probably couldn’t) control politics and public life closely at the local level, it still assiduously collected taxes and the emperor could grant communities greater autonomy. What’s more, a number of changes in the Empire’s legal and bureaucratic structures in the century before Constantine made these structures, however weak, and their “culturally coercive capacity” even more important to the standing and prosperity of the Roman landowning elite.
If an elite landowner wanted to earn imperial favor and either maintain or advance his place in Roman society, in other words, he’d do well to convert to Christianity—or at least go through the motions. As Heather puts it, “If they wanted imperial favours, even non-Christians had to adapt to the new religious climate.” Take the colorful example of Pegasios, the bishop of Ilios (the site of ancient Troy) when the Emperor Julian came to power and made an attempt to revive the old pagan ways during his brief reign in the early 360s. Pegasios had reassured the previous Christian emperor that he’d destroyed the pagan temples in his bishopric, but had instead preserved them—and then sought to become a priest in the new pagan religious order Julian intended to set up. Conversion to Christianity was not all one thing or another in the century after Constantine; genuine changes of belief like Augustine’s existed alongside the probably more prevalent and flexible adaptations that individuals like Pegasios made to the new imperial religious dispensation.
Indeed, much the same occurred for many of these same landowning elites in many of the same places in the centuries that followed the initial Arab-Muslim conquests in the seventh and eighth centuries. Conversion to Islam took a long time and not until the late 800s in Egypt and the mid-900s in Syria did majorities of the local population adhere in some way to the new religion—and often for many of the same reasons their ancestors converted to Christianity. With a new empire favoring a new set of religious beliefs, Heather notes, individuals and communities without strong allegiances to the old ways “might well wish to convert to escape and increasingly well-defined second-class social status.”
Equally important to Christianity’s long-term success was its perceived association with military and political strength. When Christian kingdoms and polities were seen as powerful, they exerted a gravitational pull that attracted nearby political leaders who aimed to solidify their own power both at home and abroad. Indeed, interest in Christianity among foreign elites in northern and eastern Europe ebbed and flowed with changing perceptions of the power of Christian states. The Goths, for instance, expelled Christian officials when they “managed to assert greater diplomatic independence” from the Roman Empire in the late 340s—only to convert en masse to the then-favored version of Christianity as part of the deal struck for refuge in the Empire in the face of Hunnic attacks.
Same goes for a number of central and eastern European kingdoms in and after the era of Charlemagne in the late 700s and 800s. The new dynasties that arose in these parts of the continent sought to unify their societies, and emulated religious and political ideology of the then-dominant local power: the Carolingian empire and its successor states, including the Holy Roman Empire. For these emerging rulers, Heather argues, “the whole apparatus of government associated with their impressively imperial Christian neighbors… must have provided an attractive model of what rulership could be.” It also offered lesser dynasts a way to defend themselves against “a potentially predatory dynastic neighbour” via an alliance with an even stronger Christian power.
When the power of these Christian kingdoms waned, however, so too did their attractiveness as a model worthy of emulation by other up-and-coming polities. Norse rulers, for instance, accepted Christian missionaries when Carolingian power was at its peak in the early 800s, only to savagely turn on them as the empire fragmented in the middle of the ninth century. Norse polytheism underwent a violent revival at the same time Viking raids spread across littoral Europe, destroying churches and other Christian religious institutions along the way. Only in the 960s would the Vikings finally convert to Christianity. In the centuries that followed the collapse of the western Roman Empire, Heather writes, “the astonishing geographical spread of Christian allegiance was clearly predicated on the upon the existence and power of Christendom’s new imperial dynasties.”
Like his Roman imperial predecessors, Charlemagne and his successors helped determine the shape and nature of Christian belief and practice—and unwittingly laid the foundation for the authority of the Roman papacy that emerged after the turn of the millennium. The First Crusade that seized Jerusalem in 1099 only cemented the papacy’s authority, its improbable success against all odds adding “enormous lustre to papal prestige—the same kind of proof positive Divine support that Constantine and Charlemagne had both previously drawn from victorious warfare.” By the time the papacy fully asserted its authority at the Fourth Lateran Council in 1215, what we now recognize as “medieval western Christendom” was fully in place.
Finally, there was outright physical coercion—though as Heather notes, such violent campaigns tended to come later in the historical process than we might imagine. Widespread destruction of pagan temples and imperial edicts against the old practices only took off in the last two decades or so of the fourth century, after a critical mass of Roman elites had converted to Christianity and effectively licensed coercive violence against paganism. Similarly, military campaigns against the Saxons under Charlemagne and Baltic pagans by crusaders forcibly converted those populations. Later, inquisitions and other forms of persecution and intimidation were intermittently brought to bear to enforce prescribed Christian orthodoxy on medieval Europe.
What can this history tell us today? Quite a lot, actually.
Whether good or bad, ideas can be imposed from the top down. What matters is whether or not people think they can get ahead—or at least hold on to what they’ve got—if they conform to the favored or reigning religion, ideology, or belief system. Certain options become more attractive to personal advancement, whether material or simply social, when they’re clearly preferred by the powers that be, as Christianity was in the Roman Empire after Constantine. The state is the most important and influential of those powers for obvious reasons, but it’s not the only one—and the same dynamics can apply to other organizations like political parties, universities, and corporations.
In general, then, most people respond and adapt to their circumstances order to survive and, hopefully, prosper—that’s as true today as it was two millennia ago. Heather himself invokes an analogy to the communist party-states of Cold War era Europe, noting that the “vast majority” of individuals “would always choose to join the party, because it was the only available path to the best possible everyday life.”
Likewise, Donald Trump’s hostile take-over of the Republican Party changed the incentives for political survival within the party itself and gave previously marginal notions far more attention than they merited. Those Republicans who refused to go along with Trump have seen their political careers end, while others have attempted to follow in his political footsteps. Most elected Republicans, however, simply went along with the new dispensation and received long-sought ideological rewards like conservative Supreme Court justices or massive tax cuts for the wealthy.
When it comes to foreign affairs, it’s clear from Heather’s account that the power of attraction matters. Ideas spread based on the perceived success of those societies that embrace them, leading others to emulate them. The Soviet example is instructive: it’s hard to believe that communism would have spread as far as it did around the world without the Soviet state to serve as a source of ideological inspiration and imitation—as well as funds and other material support. But it can work the other way too: President Franklin D. Roosevelt’s New Deal, for instance, kept the fire of liberalism and democracy burning at a time both communism and fascism threatened to douse it, not least in the minds of wavering elites in democratic nations themselves.
None of the calculations governments and political leaders make under these circumstances are all that sophisticated. In many cases, they’re rather simple and echo the sort of ideological and religious conformity practiced by individuals within societies. But this very simplicity underscores the importance of making sure America and its allies succeed at home—and help fellow democracies like Ukraine do so abroad.
If it does nothing else, Christendom exposes the rather shallow nature of contemporary political and policy debates about the relationship between power and ideas—particularly those put forward by self-proclaimed foreign policy realists. Ideas may not drive the world all on their own. But we neglect them and the way they interact with power at our peril.