Decisive Battles: Milvian Bridge (312)

The Roman cavalryman sees the host of Maxentius just up ahead, near the bridge over the Tiber. The Eternal City lies just beyond, gleaming in the distance. The enemy army is huge, and though he’s well-trained, he can’t help the palpitations beating against his chest. A glance at his shield reveals the odd Christian symbol his Emperor had told him to fight under. Would this really lead to conquest? Or was Constantine just another nut in purple? The Empire had seen no shortage of those in the past century!

This is a preview of the Battle of Milvian Bridge chapter in the Critical Battles series. Click here to get the full thing at the Masculine Epic Patreon page.

The Background

The Roman Empire showed an amazing amount of religious toleration. Not until the Age of Enlightenment had run its course would such toleration be the norm again. Some of this was politically motivated. Should Rome attempt to enforce a single religion over an area that stretched from the Atlantic to the Euphrates and from Scotland to the Sahara, there was no way, even at its zenith of power, that it could have dealt with the revolts that would likely have come all throughout the Empire. It was indeed, troublesome enough for the Romans to put down the religiously-motivated revolts in the little province of Judea alone. However, politics cannot be the only explanation for this occurrence. Polytheistic religions by their nature require less intolerance than monotheistic ones. If there are many gods. then one god cannot as a rule be infallible. The Romans as a people were not closed to the idea of new religious possibilities. Religion in the Roman Republic and early Empire was not an all-or-nothing game, as it came to be in later ages.

There was only one religious duty that the Empire demanded of its inhabitants. That duty was to acknowledge and make sacrifices to the Imperial Cult, which deified the Emperor as a symbol of unity throughout the Empire. Only Jews were exempted, out of respect for their ancient religious heritage. This duty was something that Christians refused to perform and it was this refusal that caused them to be persecuted.

Persecution of Christians tended to happen in waves, rather than in one constant, overwhelming crackdown. Mass persecutions in varying forms came under Nero, Maximus Thrax, Decius, Valerian, and most recently for the time we are studying, the Emperor Diocletian, who reigned from 284-305, when he abdicated. Diocletian’s crackdown is called the Great Persecution.

While the number of Christians throughout the Empire had steadily increased during the three centuries after Jesus’ death, despite the persecution, they were still a small minority at the time of the Battle of the Milvian Bridge in 312. Gibbon estimates that it was no more than a 20th of the Empire’s population, based on their numbers in Rome. Since Rome had the largest congregation of all, that was indicative of the religion’s numbers throughout the Empire, or so his logic went.[i] Others disagree with his tabulation. There was a larger proportion of Christians in the Empire’s eastern provinces, for example, but the point remains that Christians were nowhere near a majority. It is by no means evident that, at the start of the Fourth Century, Christianity would become by the end of that century the official religion of the Roman Empire and come to dominate the Western religious mind.

Battle of Milvian Bridge 312
Constantine supposedly saw a Christian sign in the sky before the Battle of Milvian Bridge in 312.

When the Emperor Diocletian came to the throne, he inherited an Empire fraught with problems. Historians call this situation the “Crisis of the Third Century,” and it consisted of military, economic, and social convulsions that threatened the Empire’s existence.

For all of its advances in the realm of law, the Roman Republic, and later the Empire, had no written constitution. It was governed, much like the United Kingdom is today, by an uncodified constitution that relies on precedent. However, unlike the modern United Kingdom, precedent in the Roman Empire was much murkier, as there were no written legal documents to give weight to any governmental customs, such as the 1689 English Bill of Rights. Roman Emperors had what amounted to absolute power, but the rules of succession were never clearly defined. The shifting loyalties of the Roman Legions added to this already tenuous situation. They increasingly became loyal not to the state itself, but to their commanders and those that would reward them.[ii] These elements set the stage for a number of succession wars which eventually spiraled into secession from the Empire itself. To show how this precipitated the decline of the Empire in the Third Century, we can compare it to the previous one.

During most of the Second Century, there were a total of five emperors. This period is known as the time of the “Five Good Emperors” and is considered the peak of Rome’s power. These were strong emperors who could govern the Empire properly and command the loyalty of the military.

Things began to unravel even before the Third Century began. In the 100 years prior to Diocletian’s accession, there was a grand total of 29 emperors, along with six more co or junior emperors. The civil wars that resulted from this situation greatly weakened Rome’s military. During this time there seemed to be no surer death sentence than donning the imperial purple.

The political and military situation further eroded a Roman economy that had already been weakened. Roman Emperors had found themselves short on money previously, and resorted to an age-old method of redress that still lives with us to this day: devaluing the currency. At first this devaluation was gradual. During the Third Century however, the political unrest made it a matter of utmost necessity that emperors keep the army happy with regular pay and bonuses. If such pay was refused, revolt was likely. These revolts had the effect of breaking down the Roman trade network, causing further economic decline.

Diocletian was the strongest emperor since Marcus Aurelius 100 years before, and his reforms were the most far-reaching since Augustus. For our purposes we need not go over them in detail but for two – his policies to divide the Empire and to persecute Christians.

Diocletian understood that the Empire was too far-flung for one man to effectively control in time to respond to emergencies. Perhaps this hadn’t been the case at one time, but the changes in the army and economy now made it impossible, he reasoned. To strengthen the government and avoid further unrest, Diocletian divided the Empire into two halves – East and West. Each half would be ruled by a senior emperor, called the Augustus. The senior emperors would in turn be assisted by a junior emperor for each half, the Caesar. This system was known as the Tetrarchy. To ensure the loyalty of the other emperors, Diocletian took their sons as hostages in his court.

Roman Tetrarchy Milvian Bridge
The original Roman Tetrarchy, prior to Constantine and the Battle of Milvian Bridge in 312.

On the religious front, Diocletian was a pious man who sought a religious revival within the Empire. This was a time of crisis, and religion could become a powerful method of imperial unity. Dangerous religions undermined the moral fabric of the Empire and risked angering the gods. As a result of this worldview, the Tetrarchy issued a declaration against the Christians in 303. Churches were destroyed and Christians began to be imprisoned and ordered to make sacrifices to Rome’s gods. The proclamation targeted the Church higher-ups in particular.[i]

It is true that the persecution in the West was not as widespread in the East. Tellingly, Eusebius devotes no chapters on the territories in the Western Empire. The Western Emperor Maximian and his junior Emperor, Constantius, simply didn’t show as much interest. However, Christianity’s vulnerability as a faith was still very much in place. There was nothing to suggest that if subsequent Emperors sought to persecute Christians, there would be much to stop them from doing so.

We now first see the name of Constantine in the annals of history. He was the son of the Western Caesar, Constantius, and grew up as a hostage in Diocletian’s court.

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[i] Eusebius of Casarea. Church History. Book 8, chapter 2. Translated by Phillip Schaff. WM. B. Eerdman’s Publishing Company. Grand Rapids, MI. 1890. Retrieved March 28th, 2021.

[i] Gibbon, Edward. History of the Decline and Fall of the Roman Empire. Chapter 15. 1776 Retrieved March 28th, 2021.

[ii] Peden, Joseph R. “Inflation and the Fall of the Roman Empire.” October 27th, 1984. Mises Institute. Retrieved March 28th, 2021.

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