Emperor Constantine was a Disaster for the Christians in Persia

The following is an excerpt from The Silk Roads: A New History of the World by Peter Frankopan. I particularly want to highlight how the Christians in Persia were foolish to think that their problems were going to end because the "Christian" Roman Emperor was going to conquer Persia and establish Christianity. The Persian Christians thought of the Kingdom of God as something to be formed on Earth, even though Jesus said, "My kingdom is not of this world." This made the Persian Christians come across as traitors to the Persian government, and when the help didn't come, they were terribly persecuted, due to their own actions and their ignorance of what Jesus advised them to do.
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Constantine’s celebrated conversion marked the start of a new chapter in the history of the Roman Empire. Although Christianity was not made a state religion, the easing of restrictions and punishments opened the floodgates for the new faith. This was good news for Christians and Christianity in the west, but it led to disaster for Christianity in the east. Although to start with Constantine was a tactful convert, issuing coins bearing distinctly pagan images and erecting a statue of himself as Helios-Apollo in his new city, he soon became more strident. Before long, he was portraying himself as the protector of Christians wherever they were—including outside the Roman Empire.
In the 330s, rumour spread that Constantine was preparing an attack on Persia, exploiting an opening presented by a disaffected brother of the Shah who had sought sanctuary at the Roman imperial court. Persian nerves must have jangled when a letter was received from Constantine announcing that he was delighted to have learnt that “the finest provinces of Persia are filled with those men on whose behalf alone I am at present speaking; I mean the Christians.” He had a specific message for the Persian ruler Shāpūr II: “I commend these persons to you for your protection . . . cherish them with your customary humanity and kindness; for by this proof of faith you will secure an immeasurable benefit both to yourself and us.” This might have been meant as gentle advice, but it sounded like a threat: not long beforehand, Rome had rolled its eastern frontier deep into Persian territory, and immediately set about a programme of fortification and road-building to secure these gains.
When the ruler of Georgia, another Caucasian kingdom of commercial and strategic value, experienced an epiphany that was only marginally less colourful than Constantine’s (the king literally saw the light after being engulfed by darkness while hunting), anxiety turned to panic. With Constantine absent on the Danube frontier, Shāpūr II launched a surprise attack into the Caucasus, deposing one of the local rulers and installing his own nominee in his place. Constantine responded immediately and dramatically: he assembled an enormous army and, ordering his bishops to accompany the forthcoming expedition, arranged for a replica to be made of the Tabernacle, the structure used to house the Ark of the Covenant. He then announced that he wished to undertake a punitive attack on Persia and be baptised in the River Jordan.
The scale of Constantine’s ambition knew no bounds. He minted coins in advance, giving his half-nephew a new royal title: ruler of Persia. Excitement spread quickly among Christians in the east, captured in a letter written by Aphrahat, head of an important monastery near Mosul: “Goodness has come to the people of God.” This was the moment that he had been waiting for: Christ’s kingdom on earth was about to be established once and for all. “Be certain,” he concluded, “the beast will be killed at its preordained time.”
As the Persians prepared to mount fierce resistance, they had a huge stroke of luck: before the expedition could get going, Constantine fell ill and died. Shāpūr II proceeded to unleash hell on the local Christian population in Persia as a reprisal for Constantine’s aggression. Egged on by the Zoroastrian authorities, the Shah “thirsted for the blood of the saints.”
Martyrs were made by the dozen: one manuscript from Edessa at the start of the fifth century records the execution of no fewer than sixteen bishops as well as fifty priests in this period. Christians were now regarded as an advance guard, a fifth column that would open Persia to the Roman Empire in the west. Leading bishops were accused of making the Shah’s “followers and people rebel against [his] Majesty and become slaves of the emperor who shares their faith.”
This bloodbath was a direct result of the enthusiastic adoption of Christianity in Rome. The persecutions unleashed by the Shah stemmed from the fact that Constantine had elided the promotion of the Roman Empire with that of Christianity. The Emperor’s grand statements may have impressed and inspired men like Aphrahat, but they were immensely challenging for the leadership in Persia. Roman identity had been clear-cut before Constantine’s conversion. But now the Emperor—and his successors—was willing to talk of protecting not only Rome and its citizens, but Christians in general too. It was a convenient ace to play, not least at home where the rhetoric was bound to go down well with bishops and the faithful. For those living beyond the empire’s borders, however, it was potentially disastrous—as Shāpūr’s victims found.
It is ironic, therefore, that while Constantine is famous for being the Emperor who laid the basis for the Christianisation of Europe, it is never noted that there was a price to pay for his embrace of a new faith: it spectacularly compromised Christianity’s future in the east. The question was whether the teachings of Jesus Christ that had taken hold deep in Asia would be able to survive a determined challenge.