There is a wide range of sources for the relationship between pagans and Christians, both peaceful and hostile. It is important to first point out though that Christians were very much part of the Roman world, not outsiders and certainly not a group limited to the poor, even before their official integration into imperial institutions. As a result, Christians ought not be seen as the polar opposite of pagans, but their neighbours, friends, and enemies who just happened to believe in something else. For more on this, see D. Boin, Coming Out Christian in the Roman World: How the Followers of Jesus Made a Place in Caesar's Empire (2015). Then there is the problem with the nature of the evidence, as we are largely limited to the privileged perspective of urban educated elites. So this is mostly what I'll be discussing here, not the attitudes of ‘average’ Romans, which is much harder, if not impossible, to uncover.

After Christianity was legalised and then given imperial patronage by Constantine I, the imperial government was also Christianised. This was partly because Christian emperors tended to appoint their fellow-believers, but also because if you wanted to get ahead in this world, it made sense for ambitious men to follow the imperial lead in their beliefs. But this is not the whole story. We know, for example, that there remained a substantial group of pagans in the Roman Senate, perhaps even a majority, so many important fourth-century officials were in fact pagans, most famously the praetorian prefect Praetextatus and the aristocrat Symmachus. They were hardly the people who would want to bring the Christian empire down, since they had a very privileged place within it!

They did of course engage in disputes with their Christian acquaintances, but that is just another aspect of their complicated social world, not necessarily the dominant one. One good example is Symmachus' petition to succeeding emperors on behalf of the Senate to restore the Altar of Victory to the Senate House, an effort that was resisted by Bishop Ambrose of Milan. The pagan urban prefect had similarly tried to bring non-Christians into court, most famously by recommending the Manichee Augustine of Hippo (before he (re)embraced Christianity) to become the new professor of rhetoric in the imperial capital of Milan. Yet this is not the fully story, since Symmachus was still governing the empire on behalf of a Christian emperor and giving patronage to all manner of ambitious young men, including Christians.

Beyond Symmachus, there were two major conflicts generally associated with a pagan fightback, but both are now contested by historians. One took place under the pagan emperor Julian, as he tried to institutionalise pagan beliefs to counter the Church. Yet his strategy was also not particularly effective or partisan - pagans in Antioch for instance disliked Julian's innovations, and the pagan emperor had also given patronage to Donatist Christians, as opposed to the ‘orthodox’ Church. Julian's goals therefore look to me to be an attempt to remove the influence of the institutional Church on government, not an attack on Christianity itself.

The second example is the so-called ‘pagan last-stand’, when the usurper Eugenius seized the Western Roman Empire in 392. The problem of course is that Eugenius was himself a Christian. Historians in the past has nonetheless given him a significant role in ‘defending’ paganism, as this revolt was backed by powerful pagan aristocrats, such as Nicomachus Flavianus, and Eugenius did allegedly give extensive gifts to these pagans. But as more recent historians have pointed out, this is what any usurper would do anyway, since keeping your most powerful supporters loyal by granting gifts and offices is a sensible thing to do on any occasion. The fact that there were still powerful pagan aristocrats at this point in fact tells us a lot about how complicated this Christian empire was! In any case, the equally influential Symmachus lived through this war and his family remained politically active - simply because he did not back the usurper (even if he was personally linked to Nicomachus). The true purposes of this conflict were further warped by the rhetoric surrounding Theodosius I’s eventual victory, which was naturally proclaimed by his allies as the result of God’s favour. Religion was no doubt important for many people, but we also have to take into account political factors, or even personal ones. Dividing people into neat categories is unfortunately rather difficult, if not impossible.

The most interesting scholarly argument put forward recently is that of Alan Cameron, whose The Last Pagans of Rome (2010) argued forcefully for the view that paganism was already a dying force in the fourth century, so much so that many of the texts we traditionally see as pagan or as written by pagans were instead written by Christians who were no less keen on classical mythology than their pagan ancestors. There is an important point here, since Christians continued to use pagan philosophy and myths in their education long after paganism itself was invisible amongst the imperial elite, but I suspect that Cameron went too far. To describe an entire group as on the decline does not do justice to the individuals we find in the sources. Symmachus and Praetextatus were for example very successful at court, likewise for Nicomachus before he decided to commit treason. They lived complicated lives and it is clear to me that they sought to promote their beliefs in a changing world - Praetextatus’ widow for example loudly proclaimed her husband’s religion in his funerary inscription, whilst Symmachus’ appeal to the emperor to restore the Altar of Victory tells us a lot about his priorities (and also that the politically astute Symmachus thought that he had a reasonable chance of successfully persuading the Christian court!).

What Cameron got absolutely right is the need to read sources more carefully, to not attribute every instance of violence to religious tension. A good example comes from Egypt. Riots in Alexandria were a well-known institution throughout antiquity, so it would be incorrect to see the lynching of Hypatia, a pagan philosopher and a figure made famous in recent years, only as the results of religious conflict. Hypatia, in reality, was close to the (naturally Christian) governor of Egypt and was the unfortunate victim of a vicious struggle in the city between the bishop and the governor. Even as late as the sixth century, we can still find prominent pagans, such as Zosimus, a bureaucrat-turned-historian who wrote an angry history blaming everything on Christianity, but who had evidently nonetheless thrived in a Christian institution. More extraordinarily, Severus of Antioch, a contemporary theologian, was himself of pagan origins and only converted when he was a student in Beirut.

I do not intend here to gloss over the violence and heated rhetoric of late antiquity, but it is essential to understand that no-one had sought to overthrow the Christian world order, that there was no genuine pagan revolt, and that coexistence was perfectly possible. Christians and pagans, at least the ones we know of, were educated through the same classics and were expected to follow the same career trajectories. Religious disputes did take place, but characterising the two groups as their mutual antithesis is entirely ahistorical. Instead, we have to understand conflicts on their own terms, to try to uncover all the factors involved. To do otherwise would be playing into the hand of contemporary polemicists, who did want to paint the world as only made up of black and white, of Christians against pagans, when the reality was, as always, much more complex.