Between AD 222 and 312, Parthia falls to Persia, and Diocletian tries to save the Roman Empire, leaving Constantine to finish the job
IN 222, THE SAME YEAR as Elagabalus’s murder, the Parthian king Artabanus V managed to defeat his challenger and take back Ctesiphon.
He held his capital city for only two years. The young Persian Ardashir had managed to build a following from the old Median and Persian cities and their allies, and he had now fortified himself at his home city of Gur. In 224, he and his army advanced forwards to meet the Parthian hordes at the plain of Hormizdagan.
In the battle, Artabanus V was killed. The Parthian empire had ended; now Ardashir moved into the palace at Ctesiphon and declared himself, in the old Persian way, to be Ardashir I, King of Kings. His new dynasty took its name, the Sassanians, from his own native Persian clan.
The Parthian empire, which had evolved from a nomadic takeover, had operated as a set of vassal kingdoms that reported to an overall king. This, as Ardashir I knew from experience, gave rebel kings too much freedom to rebel. Instead, he organized his new empire into something more along old Persian lines. He divided it into provinces, or satrapies, under military governors; these were intentionally laid out across and through the old kingdom borders, to break up any alliances which might be tempted to form after the overthrow of Artabanus V. Governors who were members of his own royal Sassanian clan were known by the honorary Persian title of shah.
For the Romans, afflicted with one useless king after another, the resurrection of the Persians must have seemed like the return of a monster from an old dream. Ardashir I, the first Great King of the new and restored Persian dominance, ruled until 241 and then passed on to his son Shapur a well-organized empire, ready for expansion.
Coins from the end of his reign show Ardashir facing a younger prince; he seems to have crowned his own son co-ruler before his death. The ninth-century Arab historian Abu al-Mas’udi, who like Herodotus travelled through the known world and collected ancient traditions to weave into a history, says that Ardashir put his crown upon Shapur’s head with his own hands, and then withdrew so that Shapur could rule alone.1 This indicates a man with the future on his mind (something which had not been conspicuous in the Roman emperors of the last few decades).
Shapur I began his career as king by calling on the great god Ahuramazda to support his claim to the throne. Both Ardashir I and Shapur I were Zoroastrians, adherents of a mystical religion first preached by the prophet Zoroaster (or Zarathustra) back in the days of Darius I. Zoroastrianism had a complicated theology and even more complicated rituals, but by the time of Shapur I it taught that the universe was divided into two equally powerful opposing forces of good and evil. Good emanated from the being of the great god Ahuramazda; evil resided in the opposing deity Ahriman.2362 This dualism meant that good and evil were in eternal conflict, and that the followers of Zoroaster were committed to an unending battle against the forces of wickedness, represented by demonic spirits called daevas. “I curse the Daevas,” begins the ancient creed attributed to Zoroaster himself, “I declare myself a Mazda-worshipper, I ascribe all good to Ahuramazda. I want freedom of movement and freedom of dwelling for those with homesteads, to those who dwell upon the earth with cattle…. Of all religions that exist or shall be, [it] is the greatest, the best, and the most beautiful.”3
Shapur had no hesitation in claiming Ahuramazda’s sanction on his divine right to rule; there was no negotiating around the sensibilities of his people. As king of Persia, he was the champion of righteousness. Ardashir himself had proclaimed Zoroastrianism the state religion of his new empire, which drew every one of his subjects together into a holy community with a single purpose. Every subject of Shapur was a soldier against the daevas; the loyalty of every man and woman to Persia was also a commitment to the constant fight against evil. The official religion was also a tremendously powerful nation-maker.
Shapur’s armed conquests began with the Roman giant. He managed to capture the Roman garrisons in Mesopotamia and then marched into Syria to face the Roman forces in the Syrian province. This initial Persian thrust at Rome failed; Shapur’s army was defeated by the Syrian legions, and the Persians were forced to retreat.237 But despite this successful parry, Rome’s ability to keep off Persian attacks was seriously strained. Rome was also facing a new enemy to the north.
85.1 The Gothic Invasion
Sometime in the second century, peoples who had long lived on the northern peninsulas which we now know as Scandinavia crossed the strait in boats and landed on coast of Europe. The sixth-century writer Jordanes, our best source for what happened next, begins their history here: In the “arctic region,” he writes, there is “a great island named Scandza, from which my tale (by God’s grace) shall take its beginning. For the race whose origin you ask to know burst forth like a swarm of bees from the midst of this island and came into the land of Europe.”4
These newcomers were known to the Romans as the Goths. Jordanes calls them “many and diverse,” and lists a whole array of tribes that fall under the general name of Goth: Screrefennae and Finnaithae and Finns, Dani and Grannii and many more. They were a tough and resilient people, he adds, “like no other race in their sufferings and blessings, because during the longer days they see the sun returning to the east along the rim of the horizon, but on the shorter days it is not thus seen.”5 Accustomed to twenty-four-hour days and nights, the Goths were comfortable with extremes.
In Europe, they fought their way through the Germanic tribes down to the Danube, and some made their way over to the east, towards the old territory of the Scythians. Jordanes after this divides them into two groups: the Visigoths, or “Goths of the Western Country,” and the Ostrogoths, the eastern half. The Visigoths were now threatening the Danube into Roman territory, while the Ostrogoths were overflowing into the old lands of Thrace and Macedonia.
By 249, the threat of invasion from the north had become acute enough for the army to take matters into its own hands. The current emperor, the forgettable Philip,238 had tried to buy the Goths off with tribute payments, and had fallen behind on his installments, upon which the Visigoths crossed the Danube and ravaged the countryside. The troops near the Danube, disgusted, declared their general Decius emperor instead; some of them, Jordanes says, simply deserted and went over to join the Goths.
Decius lasted exactly two years. After he went down to Rome to accept his new power, he went back up again to fight the invaders. In 251 he was killed in battle, just below the Danube. He was the first Roman emperor to fall while fighting against an outside threat; all the others had been removed by their countrymen.
When Shapur I launched his next attack against the Syrian border in 252, the Roman legions were seriously put to it to defend both the eastern borders from Persian pressure and the northern border from Gothic attack. The east broke first. Shapur I pushed through the Syrian garrisons and took all of Syria for himself. In 253, he captured the great eastern city of Antioch and sacked it.
In that same year, Rome finally got an emperor who managed to hold onto the throne for more than a month or two. Valerian had served as consul and also as general; he was nearly sixty, but for a few years it looked as though he might be able to turn the Roman luck around. He gave his son Gallienus command of the legions in the west, and while Gallienus fought off invaders near the Rhine, Valerian began to win battles in the east.
85.2 The New Persian Empire
Exactly how many is not known, but his coin of 257 calls him “Restorer of the World,” which (given room for exaggeration) suggests significant success. But in 260, plague swept through his army and weakened it. When the Persians attacked him at Edessa, he was forced to retreat, and finally to ask for negotiations.
Shapur I agreed, as long as the emperor would meet him with only a small band of soldiers. Valerian arrived at the negotiation place with few guards; Shapur I killed his retinue and took him captive.
Later church historians, who were the most complete chroniclers of Valerian’s life but who loathed him because he hated Christians, saw this as a judgment. “God punished him in a new and extraordinary manner,” says Lactantius. “[Shapur], the king of the Persians, who had made him prisoner, whenever he chose to get into his carriage or to mount on horseback, commanded the Roman to stoop and present his back; then, setting his foot on the shoulders of Valerian, he said, with a smile of reproach, ‘This is true, and not what the Romans delineate on board or plaster.’ Valerian lived for a considerable time under the well-merited insults of his conqueror; so that the Roman name remained long the scoff and derision of the barbarians.”6
A Roman emperor, still crowned, in captivity to a Persian barbarian and acting as his footstool, was about as humiliating a turnaround as could be imagined. It was certainly a big deal to Shapur, who had carved on his tomb an enormous figure of himself, seated in triumph on horseback, dragging Valerian by the arm. The previous emperor Philip is kneeling humbly in front of the horse; another emperor sprawls under the horse’s hooves.
Rome was suddenly less alarming, less all-overcoming. The provinces began to revolt. The Roman army was scraped thin dealing with rebellion and with more invasions from the north: the Germanic Alemanni tribe was making intrusions into Italy, the Franks (also Germanic in origin) were ravaging the Roman provinces on the Iberian peninsula, and the Gauls had broken away and announced themselves a kingdom in their own right.
Valerian was still captive, and still emperor; his son Gallienus was now acting emperor, more or less by default. He was a competent general, but this level of chaos was beyond fixing by any one man. He too would remain in power only as long as he proved his worth as a commander, and he could see that his days were limited. He made his enemies eat with him, in an effort to avoid poisoning; he kept around him at all times a small circle of soldiers he trusted; but in 268, one of those very soldiers killed him.
At some unknown point, his father Valerian had also died in captivity. Shapur treated his body like a trophy: “He was flayed,” says Lactantius, “and his skin, stripped from the flesh, was dyed with vermilion, and placed in the temple of the gods of the barbarians, that the remembrance of a triumph so signal might be perpetuated, and that this spectacle might always be exhibited to our ambassadors, as an admonition to the Romans, that, beholding the spoils of their captived emperor in a Persian temple, they should not place too great confidence in their own strength.”7
AFTER GALLIENUS’S MURDER in 268, the Roman Empire—just barely—held onto its existence. By 271, barbarian invaders had managed to make their way right into the middle of the peninsula. But the reigning emperor Aurelian, a soldier-turned-king whom the fourth-century historian Eutropius calls “a man of ability in war…much inclined to cruelty,”8 directed the troops into a series of well-planned campaigns which almost restored the old borders. The disintegration had been temporarily reversed, and this made Aurelian respected if not popular. “He was indeed cruel and sanguinary,” Eutropius concludes, “and rather an emperor necessary for the times, in some respects, than an amiable one…. He was, however, a reformer, in a great degree, of military discipline and dissoluteness of manners.”9
But merely whipping the army back into shape was not going to solve Rome’s difficulties. Aurelian himself acknowledged this when he ordered a wall built around the city itself. For three hundred years, Rome had had no wall; its citizens boasted that it was protected by the power of Rome’s armies.10 Now that protection could no longer be relied upon. The army’s loyalties, on which the power of the emperor now rested, were too changeable. Aurelian himself would only last five years before the Praetorian Guard murdered him in the middle of a public road.11
The Senate had put power in the hands of the emperor, the emperor leaned on the strength of the army, and Rome had too many armies on too many frontiers for this to be anything like stability. In the nine years after Aurelian, six men were given the title of emperor, and each one was murdered.
The possible exception to this was the fourth: the emperor Carus. His men claimed that he had been struck by lightning while camping on the banks of the Tigris.12 This was, just barely, plausible. On the other hand, when Carus was “struck by lightning,” the commander of his bodyguard, Diocletian, was in the camp. Carus’s son Numerian then became king, and died mysteriously while travelling with the army. He was riding in a litter because of some difficulty with his eyes that kept him out of the full sun, and when he died in the litter no one noticed. “His death…was made known by the odour of his dead body,” Eutropius says, “for the soldiers, who attended him, being struck by the smell, and opening the curtains of his litter, discovered his death some days after it had taken place.”13
This reeks of conspiracy (one wonders what “attending him” means, if the soldiers didn’t notice that Numerian had been behind his curtains for days), and before long a culprit was fingered. The army gathered to appoint a new leader, and Diocletian cried indignantly that he knew who had killed Numerian: it was Numerian’s own father-in-law, commander of the Praetorian Guard. Overcome with righteous indignation, he drew his sword and killed the man “in the sight of the army,” which did away with the necessity of investigating the accusation.14
Then Carus’s other son was acclaimed emperor by his father’s friends. Diocletian’s ambitions now came out into the open. He led his own supporters against the troops of the new emperor, and killed his opponent in the battle.
This left Diocletian at the head of the Roman empire: a man whom Lactantius called “that author of ill and deviser of misery.”15 Like his predecessors, Diocletian comes off badly in the church fathers because he too ordered edicts of persecution against Christians. Lactantius accuses him of corruption, cruelty, overtaxation, rape, and pretty much anything else he can throw into the pot, and winds up by announcing that he almost ruined Rome: “This man, by avarice partly, and partly by timid counsels, overturned the Roman empire,” he complains. “For he made choice of three persons to share the government with him; and thus, the empire having been quartered, armies were multiplied, and each of the four princes strove to maintain a much more considerable military force than any sole emperor had done in times past.”16
But in fact this division of the empire saved it. Diocletian was undoubtedly an ambitious man, but his ambition was more complex than Lactantius gives him credit for. He was not merely grasping for gain. He was looking for a solution to the problem of the empire, and he found it by giving most of his power away.
The year after he was acclaimed, Diocletian chose a right-hand man, another army officer named Maximian whom he knew well. He gave Maximian the imperial title Augustus, and offered him the job of co-emperor: the first time since the disastrous days of Caracalla and Geta that two emperors had shared the title.
He had come to the conclusion that the biggest problem of the empire was one of size. It was impossible for any one man to keep a hand on all the regions without autocratic tyranny, and autocratic tyranny led to death. Anyway, even the most autocratic emperor could not remain the favorite of troops spread from Gaul all the way over to the Euphrates. The legions were bound to favor the man who was closest to them; Diocletian gave both halves of the empire an emperor who could remain near.
The power of the army continued to worry Diocletian. In 293, Diocletian made a further arrangement to keep the army from getting involved in each change of power. He appointed two junior “emperors,” two officials who were given the title of Caesar (the usual designation that an emperor gave to his successor). These two Caesars, Constantius and Galerius, were also tied to the emperors themselves in a more personal way: Galerius married Diocletian’s daughter, while Constantius married Maximian’s. (“Both being obliged to divorce the wives they had before” Eutropius remarks.17 Stability came at a price.)
In 305, Diocletian did something no emperor yet had tried. He retired, abdicating in favor of his Caesar—and he insisted that Maximian do the same. He was growing older and wearier, but rather than clinging to power until his last breath, he preferred to supervise the transfer of power to the next generation. Maximian complied, with great reluctance, and the two men held abdication ceremonies on the same day, at opposite ends of the empire, both of them taking part in a victory parade and then, at its end, ceremonially doffing their imperial robes and putting on civilian clothes instead.18
Diocletian was making one more effort to refine that troublesome idea of Roman. Instead of submission to an emperor, the citizens of Rome were now being asked to submit to the idea of imperial authority. The change of clothing was more than public theatrics. Diocletian was attempting to demonstrate that the emperor represented Rome, for a time, but that the task of representative was greater than the personality who undertook it.
85.3 The Roman Empire, Divided
Briefly, this worked. Constantius became emperor of Gaul, Italy, and Africa; Galerius became emperor of the east; and two more Caesars were chosen to become their junior colleagues. But when Constantius died in 306, only a year after his accession, the army pushed its way back into the succession. The troops had not grasped Diocletian’s subtle redefinition of imperial power, and Constantius had been enormously popular with the army in the west. Now they demanded that young Constantine, his son from his previous marriage, inherit his power. The irrational desire for a king’s son to inherit his power, no matter what his character, had existed in the human race ever since the days of Etana of Sumer. It was still strong three thousand years later.
This was exactly what Diocletian had hoped to avoid, but now the old habits clashed with his new institution. The eastern emperor, Galerius, insisted that Constantius’s junior Severus become emperor of the west as planned. And then the lust for power (which had existed at least since Gilgamesh) reappeared as well. Maximian, who had never wanted to retire in the first place, threw his hat back in the ring. He marched on the unfortunate Severus—with the help of Constantine, who was Severus’s rival for rule of the west—and defeated him.
Now the empire was in a more complicated mess than ever before. The only man with the legal right to rule was Galerius; Severus was dead and Maximian was supposed to be retired, Constantine was supporting Maximian’s return to power and had also married Maximian’s daughter, which meant that his step-grandfather was also his father-in-law. And Maximian’s son, Maxentius, could now see that if his father became full emperor, he would be next in line—as long as Constantine, his brother-in-law, didn’t interfere.
A whole welter of battles broke out, with power shifting from one man to another, and from east to west, while the inhabitants of the empire covered their heads and waited it out. By 312, the array of conflicts had funnelled down into one looming conflict: Constantine and his army, north of Rome, planning an attack on Maxentius. Maximian himself had committed suicide two years earlier, humiliated by his inability to reclaim his old throne; Maxentius was in control of Rome, with troops of his own.
Constantine began his march down towards Rome in October. According to the church historian Eusebius, whose source for his accounts seems to have been Constantine himself, he justified this attack in a very familiar way: “Theroyal city of the Roman empire, was bowed down by the weight of a tyrannous oppression,” Eusebius writes, “…[and] he said that life was without enjoyment to him as long as he saw the imperial city thus afflicted, and prepared himself for the overthrowal of the tyranny.”19
85.1 Shifts of Power in the Roman Empire.
But the days were long past when the simple claim to be a liberator would serve to unite an empire behind a conqueror; the Romans in the capital city had seen too many liberators who offered a different version of enslavement. Constantine needed some more powerful flag under which to march.
Eusebius himself seems uncomfortable with what happened next. Constantine, considering whether he might claim some Roman god as the sponsor of his quest (something which had worked well for Shapur I over in Persia) had a vision.
A most marvelous sign appeared to him from heaven, the account of which it might have been hard to believe had it been related by any other person. But since the victorious emperor himself long afterwards declared it to the writer of this history, when he was honored with his acquaintance and society, and confirmed his statement by an oath, who could hesitate to accredit the relation…? He said that about noon, when the day was already beginning to decline, he saw with his own eyes the trophy of a cross of light in the heavens, above the sun, and bearing the inscription,Conquer by this. At this sight he himself was struck with amazement…. [W]hile he continued to ponder and reason on its meaning, night suddenly came on; then in his sleep the Christ of God appeared to him with the same sign which he had seen in the heavens, and commanded him to make a likeness of that sign which he had seen in the heavens, and to use it as a safeguard in all engagements with his enemies.20
Eusebius’s gingerly account may reflect an orthodox Christian doubt about the latter part of this vision, since Christian theology generally discouraged this kind of magical thinking. But Constantine acted on it, engraving the first two Greek letters in the name of Christ, the chi and rho, onto his helmet and placing it on his standard.
At Constantine’s approach, Maxentius and his army came out of the city and marched along the Via Flamina, across the Tiber river, to make their stand in front of the Milvian Bridge. Constantine would have to go through them to cross the bridge into the city.
Maxentius’s army outnumbered Constantine’s, but Eusebius mentions that there had been famine inside the city; possibly his soldiers were not at the strongest. Constantine’s attack turned them back towards the Tiber. The Milvian Bridge was too narrow to hold their retreat, so the fleeing soldiers tried to build a makeshift pontoon bridge beside it. The overloaded boats sank, drowning hundreds of them. Among the retreating soldiers drowned was Maxentius, dragged down into the Tiber by his armor. Constantine was master of the city; before long, he would be master of the empire as well.
85.2. Constantine. Marble bust of Constantine the Great, Emperor of Rome 306–337. Palazzo dei Conservatori, Rome. Photo credit Archive Timothy McCarthy/Art Resource, NY
Eusebius, telling the story of Maxentius’s end, cannot keep himself from quoting the words used by the victorious Israelites when they emerged from the Red Sea with the Egyptians drowning behind them: “So the victors might well say: Let us sing unto the Lord, for he has thrown the horse and chariot into the sea.”21 Those were words sung by a people whose faith was connected to their political existence as a nation; something Christians had never been. But Constantine saw in Christianity some hope for the future of his own nation. In three centuries of perseverance, that Christian identity—an identity that became absolutely central to those who held onto it, yet did not wipe out the other identities that had come before it—had proved itself stronger than any other.
The Roman Empire had drawn lines around itself, subjugated its allies, and demanded submission first to an emperor, and then to some ideal of the emperor’s authority; and the empire had grown more and more ragged and contentious. Meanwhile, the Christians had survived bloody wars and had spread across a good part of the known world. Christianity had done what Rome had never managed: it had spread out from its land of origin, from its narrow beginnings as a Jewish cult, and had become an identity which had drawn Jews, Gentiles, Thracians, Greeks, Syrians, and Romans into a single fold.
In allying himself with the Christian God at the Milvian Bridge, Constantine had turned the empire into something new. He had abandoned that fruitless quest to find a Romanness that was rooted in the city of Rome, but could also transcend it. Instead, he had chosen something else to take its place. When he went forwards into the battle with the name of Christ on his standard, he was staking his future on the gamble that this would be the key to holding the whole thing together.
This was the end of the old Rome. But it would turn out to be the rise of something much more powerful, both for good and for evil.