Undoubtedly, the most crazed and sadistic attack on Christians by any Roman emperor was the one launched after the Great Fire in Rome in 64 C.E., when Nero needed a scapegoat for the fire. According to the historian Tacitus, the Christians were already “hated for their abominations” in Judaea. The Jews, particularly the very Orthodox ones, would have liked nothing better than to see them disposed of—to gratify their apparent longing for holy martyrdom. Thus they welcomed their persecution by Nero, even though the need for it did not, according to Tacitus, convince the Romans themselves. They thought it freakish:
Nero provided his Gardens for the spectacle, and exhibited displays in the Circus, at which he mingled with the crowd—or stood in a chariot, dressed as a charioteer. Despite their guilt as Christians, and the ruthless punishment it deserved, the victims were pitied. For it was felt that they were being sacrificed to one man’s brutality rather than to the national interest.
There was no sudden transition between Nero’s obsessions and the victory of the Christians—how could there have been?—and yet, if we look back on it, it is surely possible to see in the violence of Nero’s attack on the little sect a foretaste of what was to come two and a half centuries later. The epochal event which divided the history of the Roman Empire was a battle won just outside Rome, and fought in 312: the Battle of the Milvian Bridge, which spanned the Tiber.
This battle marked—though of course no one realized it at the time—the end of the old Roman imperial system and the beginning of the Byzantine Empire. It was predicted by a line in Homer cited, with some relish, by the Roman gossip-monger and historian Suetonius when writing of the first-century Emperor Domitian: “Too many rulers are a dangerous thing.”
So indeed they proved to be.
Under Diocletian, the unified Roman Empire had split and assumed a new shape: at the dawn of the fourth century, it consisted of an Eastern and a Western empire, ruled by the tetrarchs—not one but two senior emperors, each known by the honorific “Augustus” and supported by his own “Caesar” or junior emperor, making four rulers in all.
The best-known depiction of this odd system was created by an unknown artist in Constantinople, looted by crusaders in 1204, and brought to Venice, where it was built into the façade of Saint Mark’s Basilica. It depicts two pairs of tetrarchs, the Augustus and the Caesar of East and West respectively, embracing one another. They are solid, heavy, thick-necked, and shown grasping their swords with their free hands. It is an image of firm—one might say, implacable—loyalty, though there is no indication of their names.
In the spring of 305, Diocletian, the Augustus of the Eastern Empire, as Maximianus was of the Western, had formally abdicated. He now retired to his gigantic palace, whose ruins still stand at Split, formerly Spalato, on the Dalmatian coast. He was succeeded as Augustus of the East by his fiercely anti-Christian colleague Galerius, who had moved up from his previous post as Caesar of the East (and was succeeded in that role by his nephew, Maximinus Daia). Similarly, Maximianus abdicated as the Empire’s Western Augustus and was replaced by Constantius Chlorus, up to then the Caesar of the West.
What threw this ponderous imperial game of musical chairs into chaos was that in 306 the barbarian border tribe of the Picts, ancestors of the modern lowland Scots, tried to invade Roman Britain. Constantius Chlorus would not put up with such effrontery and sailed for Britain with an army and his warrior son Constantine, determined to put the Picts down. He managed to do so; but then Constantius himself died, of unknown causes, at York in the summer of 306. This left his heir, the ambitious young Constantine, as imperial ruler of Britain, Gaul, and Spain, with the full rank and title of Augustus; but Galerius, the reigning Augustus of the East, did not want the boy to succeed him immediately. Constantine wrote to him asking to be ratified as the Augustus. Galerius would only give him the second rank, that of Caesar. Constantine accepted this, no doubt reluctantly, though with as much grace as he could muster.
But in Rome, neither the army nor the majority of the people would go along with that arrangement. For reasons too involved to go into here, stemming from their resentment at the prospect of forced tax levies, they wanted Maxentius, the son of Maximianus, as Caesar. And once Maxentius was installed, he asked his father to come back from retirement and become, once again, the Augustus. Galerius, who wanted the next Augustus to be a military strongman (but not as strong as himself) named Severus, objected to this proposal, and ordered his army to attack Maxentius. They lost; Severus’ troops mutinied and killed their leader; and this left Maxentius and his legions in command of Rome. In retrospect, though of course it would hardly have seemed so at the time, the most important thing about Maxentius’ power over Rome and its empire was, like that of Diocletian before him, his implacable dislike of the small and still rather marginal sect of the Christians.
Constantine launched himself across the Alps from Gaul, at the head of an expeditionary force numbering some forty thousand troops, perhaps a quarter of his whole army, in the spring of 312. His target was a heavily fortified Rome, where Maxentius had dug in. The cities of northern Italy offered little resistance. Some of them, notably Milan, effusively welcomed Constantine, because Maxentius’ occupation of Rome had deprived them of much of their importance and power. As Constantine advanced southward, it became ever clearer that Maxentius was preparing for a siege. But when Constantine’s force had come almost within striking distance of Rome, the Romans themselves lost confidence in their ability to resist a long siege; rumor and oracles persuaded them that Constantine was invincible, and so Maxentius realized that he would have to come out and fight, on the north side of the Tiber. The bridges across the river to Rome had all been destroyed, but Maxentius had a new, temporary one created from boats and pontoons where the more solid Milvian Bridge had stood. Across this structure, anchored against the flow of the Tiber, Maxentius and his army marched forth to confront Constantine on October 28, 312.
The result was a disaster, a rout.
In years to come, Constantine gave his version of the Battle of the Milvian Bridge and swore, under oath, that God had granted him a miraculous victory preceded by signs and omens. As he was leading his army south toward Rome, he claimed, he and every man under his command had seen a cross of light shining in the sky, with the words “In hoc signo vinces,” “In this sign, conquer.” That night, when Constantine was asleep in his tent, Christ appeared to him in a dream, holding that unfamiliar emblem of the cross, and directed him to have new standards made for his army in its form.
What could this really have meant to him? In the early fourth century, most people, Constantine included, had no idea of the symbolism of a cross. He was not a Christian, not yet, but there were some Christians among his advisers, such as Ossius, bishop of Córdoba, and they all concurred in pointing out that the cross was the emblem of the greatest of all gods, and that if Constantine adopted it he could not be defeated. Well, Constantine seems to have thought, try anything once. The pagan standards were flung away, on went the crosses, and soon Maxentius’ troops were on the run, in chaos and confusion. The boat bridge disintegrated, and Maxentius himself is said to have drowned under the weight of his armor while trying to get back across the Tiber.