The Triumph of Christianity

by Bart D. Ehrman

  This conversion proved to be a linchpin of imperial history, not just for the fate of the Christian religion but also for the workings of the Roman state. We will look at the persecution of Diocletian in a later chapter, and at the broader biography of Constantine in another. For now, we are interested specifically in his conversion and how it radically changed the balance of power, both for the persecuted Christians and for the running of the Roman government. To make sense of the conversion we need to understand some of the political and religious backdrop to the story.

  CONSTANTINE’S RISE TO POWER

  By the end of the third century CE, the empire was too vast and complex to be ruled by one emperor. It reached from Britain to Iraq and entailed virtually all areas connected to the Mediterranean, north into modern Europe, south into North Africa and Egypt, and east into Palestine and Syria, all the way to Persia. For many years it had been riven by internal disputes and foreign invasions. The year 284 CE is usually cited as the end of the major upheavals collectively known as the “Crisis of the Third Century,” a half century filled, internally, with imperial assassinations and usurpations involving some twenty-one legitimate emperors and thirty-eight usurpers. In addition, the empire had, for a time, been fractured by two breakaway states, one in the far west and one in the east. These had literally fragmented the empire and made the actual “Roman” state a slice of its former self. That is not to mention the incursions on the northern borders by barbarian hordes.5

  The brilliant emperor-general Aurelian (ruled 270–75 CE) had defeated and reintegrated the breakaway states, but it was not until the reign of Diocletian that a fuller sense of order was restored internally, and with it a relatively secure border on the frontier. Diocletian was one of the truly great political administrators of Roman antiquity. His predecessors, including Aurelian, had never managed to bring any semblance of stability: Diocletian’s eight immediate predecessors had all been murdered, some of them within weeks or even days of taking the throne. He himself was to enjoy a reign of over twenty years. Diocletian was the first emperor of Rome to abdicate voluntarily.

  Diocletian is best known to casual readers of Roman history as the great persecutor of Christians. This he certainly was, as we will see more fully in chapter 7. But, even more, he was an insightful and creative leader and administrator. Among other things, he devised the first sensible system for the transfer of power from one emperor to the next. Despite its theoretical virtues, however, the system broke down just over a year after the first transfer occurred, and Constantine himself played a definitive role in that collapse, leading to his own assumption of imperial power in a reign that was second only to that of the great Caesar Augustus himself in both length and historical consequence.

  From the time of Augustus, the first of the Roman emperors, the major political problem at the pinnacle of power had always been the succession. Once an emperor died, who was to succeed him? Augustus himself—unlike many of those who came in his wake—certainly had plans, and they always involved heirs who actually shared his bloodline. But one by one these potential successors died—or, if we believe the rumors, were assassinated—until virtually the last man standing was Augustus’s stepson Tiberius. As emperor, Tiberius too had no legitimate heirs to the throne, and so the world inherited Gaius, otherwise known as the infamous Caligula. The succession went from there, not always happily.

  Diocletian decided that there had to be a better way. He himself reigned with an iron fist for nearly a decade before carrying out his design. He devised a system of succession based not on dynastic ties but on merit. It was a plan to keep the empire completely unified, but ruled through a college of four emperors, an administrative unit known as the Tetrarchy (“rule of four”). There would be two senior emperors, each labeled an Augustus. Beneath each of them would be a junior emperor called a Caesar. The Caesars would be chosen based on their experience and qualifications. They would not be blood relatives of the Augusti.

  And so it happened. Diocletian became the senior emperor of the East, with a military man named Galerius as Caesar; another military officer, Maximian, became senior emperor of the West, with Constantius—the father of Constantine—as his Caesar. Even though each emperor had principal responsibility for a distinct set of provinces, the empire was not technically divided into four units. Instead, the four were construed as co-rulers of a unified empire. The decisions of one were affirmed by the four; the conquests and victories of one were credited to the others. There were four emperors, but the empire was one.

  Most important was the rule of succession that Diocletian devised. When an Augustus died or abdicated, his Caesar would then “move up” and assume his vacated position, and a new Caesar would be chosen by the most senior of the two Augusti.6 This new junior emperor would not be the natural son of the newly elevated Augustus but a figure uniquely qualified for the position. And so, in theory, the system could continue indefinitely, since successors would always be chosen—well in advance—for their abilities to perform the tasks of office, not because of the accidents of birth. It was a completely novel and rather ingenious conception.

  It was also doomed to failure. The children of current rulers could hardly be expected to accept the new system passively, and they didn’t.

  Because of health issues, after a long and successful reign of over two decades, Diocletian decided to retire from office on May 1, 305. For the sake of a smooth succession, he compelled his rather unwilling co-Augustus, Maximian, to do the same, to make way for the two Caesars, Galerius and Constantius, to rise to the senior offices. For their replacements, according to the principles that Diocletian had devised, two Caesars were chosen as junior emperors: Maximin Daia (not to be confused with the outgoing Augustus Maximian) to serve with Galerius in the East, and Severus to serve with Constantius in the West. There was now a “Second Tetrarchy.”

  At the time it may have seemed like a smooth and unproblematic transition, and in a sense it was—until one of the new Augusti died. Then the plan of succession based on qualifications ran afoul of both the dynastic principle and the army.

  The background to the story involves the new Augustus of the West, Constantius, and his son Constantine.7 Constantine had risen through the ranks of military and political service over the years, as was natural for a scion of such a high-ranking official. He had served as a junior military officer in the court of Diocletian and then, for a brief time, under Galerius. When Galerius was promoted to be the new Augustus of the East, he realized the potential problem with Constantine, who could well expect an appointment to the level of Caesar in accordance with the traditional dynastic principle. But Constantine was not named to the position and almost certainly harbored some resentment and, possibly, some hope of remedy. If later reports are to be believed, Galerius’s solution to this potential problem was to remove Constantine from the scene by regularly putting him in harm’s way during various military endeavors. One later account, probably apocryphal, claims that Galerius, for his own amusement, once assigned Constantine to fight a lion one-on-one.

  Constantine emerged from these attempts unscathed. Soon after Constantius was elevated to the level of Augustus, he requested his son’s transfer to his own service. Whether out of relief or in a moment of weakness, Galerius ceded to the request. In later propaganda we are told that Constantine fled as quickly as he could—before Galerius could change his mind—and, taking the fastest and only state-sponsored imperial route on horseback, hamstrung the horses left behind at each way station to prevent Galerius from fetching him back on second thought.

  Constantine, in any event, made it to Gaul, where his father was stationed, and joined him in his military campaigns on the borders, accompanying him to Britain to beat back incursions coming across Hadrian’s Wall. It was there that Constantius took ill and died on July 25, 306.

  That is when the dominoes began to fall. In designating his successor in the Tetrarchy, Constantius did not choose one of his great military com
manders based on personal merit but instead selected his son Constantine—returning precisely to the rule of dynastic succession that Diocletian had wanted to avoid. The problem is that Maximian, the rather reluctantly retired Augustus of the East, also had an adult son, named Maxentius, who had, along with Constantine, felt slighted by being bypassed for a place in the imperial college at his father’s abdication. Once Maxentius saw that Constantine’s army had invoked the dynastic principle by acclaiming him ruler, he pushed to receive the same privilege. With his urging, the Praetorian Guard in the city of Rome proclaimed him emperor. He assumed control of Rome and Italy, and now the “Rule of Four” had become five. To complicate matters further, Maxentius brought his father Maximian out of retirement to assist him, so that now the five were six. But not for long.

  CIVIL WAR WITH MAXENTIUS

  The emperors Galerius, Severus, and Constantine all—rightly—considered Maxentius a usurper, and knew they needed to dispose of him. There was no choice but civil war. It was not easy or swift. Galerius, the senior of the two Augusti, directed Severus to take his army into Italy and, if necessary, lay siege to Rome. Severus did so, but many of his soldiers defected to the opposing side and he was soundly defeated in battle, personally captured, and soon thereafter forced to commit suicide.8 Galerius then decided to take matters into his own hands and attacked Maxentius from the East. He too failed to complete the mission. Finding himself unable to enforce a viable siege on the city, and experiencing numerous defections of troops, he fled Rome and barely managed to escape alive.9

  During all this time, Constantine stayed away from the fray, conducting campaigns on his northern border against barbarian threats and allowing the other leaders of the empire to fight it out among themselves. He proceeded to do nothing about the situation for six years. Over that time he learned of problems that Maxentius was experiencing in Rome—famine and food shortages resulting in riots; rampaging soldiers; unjust imprisonments and executions—and reports of Maxentius’s own profligate activities. In 312 CE he decided the time was right. In retrospect he claimed he simply could no longer allow tyranny in the capital. What he did not point out in public was that overthrowing the alleged tyrant would give him possession of Rome, all of Italy, and North Africa.

  What especially matters for our narrative here is that, in addition to the enormous political and military consequences of a Constantinian victory, there was a highly unexpected religious outcome. This was to prove even more significant for the subsequent history of the Roman world. It was during his march on Rome, Constantine claimed later, that he experienced his conversion to Christianity.

  The march itself was a thing of military beauty. Constantine demonstrated his enormous military prowess, acting boldly and swiftly, accompanying his army over the Alps and destroying all resistance en route. After several victories over Maxentius’s forces in northern Italy, along with the surrender of other strongholds that could see the writing on the wall, Constantine moved his army south within striking distance of Rome itself, in preparation for an ultimate battle with the usurper, after which he would take control of the entire Italian peninsula. That is when Constantine had a vision.

  At least, that is when Constantine later claimed he had his vision. One of the thorniest issues that biographers of Constantine contend with is the question of his vision—or, rather, his visions. As it turns out, we have several contemporary reports of several visions, all of them recorded by writers who personally knew Constantine and appear to be relating what they heard from him and/or his companions directly. As a result, it is very hard to know whether Constantine had one vision or two or three, whether the vision or visions came while he was awake or asleep, whether they came while he was still campaigning in Gaul, or en route to Rome, or stationed just north of Rome on the night before his battle.

  To make sense of the reports that have come down to us, we have to put them in the context of Constantine’s personal religious life, and that will require some further background.

  THE VISIONS OF CONSTANTINE

  We have comparatively excellent sources for Constantine’s adult life, including his own writings, laws he enacted, a biography written about him by the fourth-century Christian bishop of Caesarea Maritima and “father of church history” Eusebius, and other contemporary reports.10 But we are handicapped when it comes to his life prior to his accession to the throne, including his religious life. For this we have very slim records. We do know he was born in the northern Balkans, and we can assume that he originally participated in local indigenous religions that would have included such deities as the Thracian rider gods, divine beings astride horses. As was true of all citizens in the empire, he would also have participated in civic religious festivals, including the cults worshiping deceased Roman emperors. The Roman army too had its deities of choice; as a soldier and then commander Constantine would have worshiped these as well.11

  What we do not know is how well informed he was of Christianity in the years before his conversion. His mother, Helena, was later in life—well into Constantine’s reign—a very committed Christian, and some have suspected that she had Christian leanings even in his youth. But we simply have no compelling evidence. We have a bit more information about his father, Constantius, and some observers have claimed him too for the Christian cause, none more famously than Constantine’s biographer, the Christian Eusebius.12 It is indeed worth noting that during the original Tetrarchy, when Diocletian declared an empire-wide persecution (see chapter 7), Constantius paid the policy little more than lip service, shutting down some churches but not arresting, torturing, or martyring any Christians. Was he a sympathizer or even a devotee himself? Some historians have also been struck by the fact that one of Constantius’s daughters (with a later wife) was called Anastasia, a Greek name that means resurrection—a highly appropriate name had her father been a Christian.

  It is not likely, however, that he was. More plausibly Constantius, like the emperor Aurelian some years earlier, was a “henotheist,” revering one god as superior to all others without denying the divinity of the others. In particular, he may have worshiped above all else the god of the sun, Sol Invictus (“Unconquered Sun”). That would make sense both of the fact that Constantine himself remained a pagan prior to his march on Rome in 312 CE and of Constantine’s later ruminations about what led him to the god of the Christians.

  We have three principal sources of information for the vision(s) of Constantine that led to his conversion. The first comes to us in a flattering speech—known as a panegyric—delivered by an anonymous orator in 310 CE, before Constantine had initiated his final actions against Maxentius. The speech was occasioned by a military victory in a skirmish with Maximian, Maxentius’s father, who had been brought out of retirement. As was always the case with panegyrics, the speaker himself wrote his address and made it entirely sycophantic. Such speeches were designed to praise the recipient as one of the greatest human beings the universe had ever seen, as revealed by the subject’s activities and experiences. It was in the context of celebrating Constantine’s marvelous character that the panegyrist of 310 CE described a vision the emperor had recently had of the god Apollo, who is often associated in ancient thought with the sun and considered, then, the sun god.13

  In the speech we are told that, after winning his battle, Constantine decided to visit a magnificent temple of Apollo, probably at Grand, Vosges (northeastern Gaul, modern France). There, outside the temple, Constantine had a vision of the god himself, who offered him several laurel wreaths, each of which symbolically represented thirty years of life, thus indicating that Constantine would be allotted a preternaturally long mortal existence. More than that, the god indicated that Constantine was the one who would rule the entire world. The panegyrist did not stop there, however. He went on to indicate that Constantine was a kind of human manifestation of Apollo himself: among other things, like the god he was young, handsome, and a bringer of health.

  If any such vision
did occur—or if Constantine thought it occurred, or even simply said it did—this may well be the time at which he began to revere Sol Invictus. Possibly he became a henotheist. This would not have required him to stop being pagan, as we will see more fully in chapter 3. He still could have acknowledged the divinity of other gods and recognized the right and even obligation of other people to worship them. But he may have turned his own entire focus onto the god he considered to be above all gods, choosing—as the emperor who aspired to be the greatest and most powerful human on earth—to worship only the greatest and most powerful divinity in heaven.

  The fullest version of Constantine’s vision, or visions, appears in a record produced nearly three decades later. It is also the most important source for Constantine’s conversion. The report appears in the Life of Constantine, a biography of the emperor by Eusebius, who had firsthand information from the emperor himself and claims that his account of Constantine’s conversion was what the emperor himself revealed and swore to be true.14

  Eusebius indicates that Constantine decided, for the good of the empire, to overthrow the tyrant of Rome, Maxentius. He knew that he would need divine help in his endeavor. To the regret of many a later historian, Eusebius does not tell us when exactly Constantine’s appeal for heavenly assistance occurred; all he says is that it was “on a military campaign he was conducting somewhere.” Whenever it was, it happened before Constantine engaged Maxentius in the final battle for Rome. Constantine reflected on his religious options and realized that, without help from above, his cause could not be won: