by Baker, Simon
FOUR EMPERORS
In the third century AD the Roman world was in crisis. In the space of fifty years (235–85) there were no fewer than twenty emperors, each falling in quick succession to political assassination or death on the battlefield. But it was not just the government that was unstable. The security of the empire too was at an all-time low. In 251 the Goths broke through the forts, watchtowers and ramparts along the border of the Danube from a region north of the Black Sea; they defeated the emperor Decius in battle and eventually sacked Athens. In 259 two Germanic tribes, the Alamanni and Juthungi, also smashed their way across the same border and invaded Italy. The worst year was perhaps 260: the Franks breached the border of the Rhine, marauded their way through Gaul and sacked Tarraco. But there was even worse happening on the eastern frontier. The emperor Valerian was captured by the Persians, enslaved and forced to live out his days bending over so that King Shapur could step on his back to mount his horse. Although Valerian died in captivity, in one sense he lived on: in a macabre inversion of deification, his dead body was stuffed and placed in a Persian temple as a warning to future Roman ambassadors. As shocking as these events were, Romans would find that there was worse in store.
For the best part of fifteen years the Roman provinces of Britain, Gaul and Spain seceded from the empire, and in 272 the Romans permanently abandoned the province of Dacia (modern-day Romania). Perhaps the most extraordinary offensive against Rome came from Palmyra, a rich, semi-independent city on the border of Roman Syria. When its king, Septimius Odenathus, died, his widow, Queen Zenobia, took control. Renowned for her extraordinary beauty, intellect and chastity, she orchestrated and led the conquest of the Roman east: Egypt, Palestine, Syria, Mesopotamia and many of the Roman provinces of Asia Minor all fell under her control before she then proclaimed her son emperor and herself took the title Augusta (empress).
The Romans fought back on all fronts. The most successful emperor was Aurelian (ruled 270–5). In the space of just five, brilliant years he won back the eastern Mediterranean, defeated Zenobia and brought her to Rome as the prize prisoner at his triumph. However, the restoration of the Roman east was just one of the many extraordinary achievements of Aurelian’s short reign. He also drove the invading German tribes out of Italy, forced them back over the northern borders and made peace with them. When that was done, he went on to restore the seceded provinces of Britain, Gaul and Spain to the empire.
But for all their glory, these exploits could not hide what had become so apparent in the third century: the vulnerability of Rome. The ambivalence of the situation is best summed up by Aurelian’s great building legacy. For the first time in the history of the Roman empire the emperor felt it necessary to surround and protect Rome from invaders with a massive wall. It was completed after his death by the emperor Probus (another successful emperor of this period) and still survives in part today. In 285, however, there would come to power a man who would extend that sense of security right across the empire.
Like many emperors of the third century, Gaius Aurelius Valerius Diocletianus (Diocletian) was not from the senatorial and political élite of Rome. He was a low-born soldier from a provincial family who rose to power through the ranks of the military. He had spent most of his time not in the city of Rome, but on the frontiers; in fact, he would travel to the imperial capital only once in his entire life. It was perhaps his experiences on the Danube that spelt out to him the importance of reform if the Roman empire were to survive the preceding decades of crisis. What is certain is that he went about the task of reorganization with extraordinary energy. His reforms focused on money and the army.
The official record of the standing army, the notitia dignitatum, shows how he bolstered the strength of the frontiers by creating new legions. He brought the army under central control and improved soldiers’ pay and supplies. In order to secure the funding of the army, the empire’s economy also needed a radical overhaul. In the course of the third century the coinage of the Roman world had become so debased that the empire reverted to exchanges in kind. Diocletian therefore improved the weight and mint of gold and silver coins, and made them uniform. He also tackled the problem of inflation, and enacted tough social legislation to ensure that tax revenues were successfully and consistently raised. In the process, he established a regular budget for the running of the entire empire.5
Finally, the emperor reorganized the provinces. In order to improve imperial administration, Diocletian broke them down into smaller regions; these in turn were grouped under twelve larger administrative units known as dioceses. The new system allowed closer supervision, as well as the resuscitation of law and finance by local governors and their staffs throughout the empire. However, these impressive, innovative measures were not his most celebrated achievement. The grand idea for which Diocletian would go down in history was his decision on 1 March 293 to create a college of four emperors to rule the Roman world. Diocletian was thus the first emperor to accept that the task of running the Roman empire was too big for one man.
The system, known as the tetrarchy (rule by four emperors), worked as follows. The two senior emperors were both given the title Augustus; Diocletian ruled the eastern half of the empire, while his partner Marcus Aurelius Valerius Maximianus (Maximian) ruled the western half. Each Augustus appointed a junior colleague, and these two deputies were both known by the title Caesar. Gaius Galerius Valerius Maximianus (Galerius) joined Diocletian in the east, while Flavius Valerius Constantius, the father of the future emperor Constantine, aided Maximian in the west. The four men resided in imperial centres pointedly closer to Rome’s frontiers (see map, page 247). In the east Diocletian’s main home was in Nicomedia (modern-day Izmit in Turkey), and Galerius’s in Thessalonica (Greece), while in the west Maximian’s home was Sirmio (Mitrovitz in modern-day Croatia), and Constantius’s was in Trier (Germany). In this way Diocletian ensured that the presence of the emperor of Rome was established in many different areas at the same time.
To shore up the prestige and dignity of the four emperors, uniformity was the key. Each city had an imperial palace, an audience chamber and a hippodrome; each man had his own staff, court and military guard. Diocletian’s court in Nicomedia reflected the style of eastern rulers’ courts. Subjects paid homage by calling the emperor ‘lord’ and prostrating themselves before him. Under the four emperors, the signs of despotism were much more overt.6 However, there was one further, key illustration of the severe nature of the tetrarchy system. A clue lies in the new names that each of the emperors adopted to emphasize the quasi-divine basis of their authority: Diocletian was called Jovius (after the god Jupiter), and Maximian Herculius (after he of the Seven Labours). The underpinning of the new regime was emphatically ancient, traditional and pagan. But in the ointment of Diocletian’s drive for uniformity there was a fly.
The single policy of reorganization across the empire for which Diocletian is infamous is his repression of the Christians. Why were they such a threat? Throughout the history of the Roman empire, the favour of the Roman gods was central to its successful creation and survival. With the sweep of conquest, new cults and religions had come within its embrace. Cosmopolitan Rome not only tolerated new religions, but welcomed them too: just as new peoples became Roman citizens, so their religions too were incorporated into the pantheon of Roman gods. Cybele from Asia Minor, Mithras from what is today Iran, Isis and Serapis from Egypt, the goddess Tanit from Carthage – all these gods and their cults came to Rome. They were both worshipped there and took on Roman divine forms. Indeed, their acceptance in Rome meant that the cults grew in stature. The message that their incorporation sent out was clear: even the gods of Rome’s former enemies now favoured Rome. The process served to weld the loyalty of Rome’s subjects to the empire.
Yet there was a limit to this spirit of Roman toleration for new cults – a line that must never be crossed. A number of small, individual cults posed no threat to state control of religion; indeed, they seemed onl
y to enrich it. But the formation of an organized, alternative community did.7 The Romans hated Christianity because they considered the worship of its one god dangerously exclusive. It was a rejection of everything it meant to be Roman. By refusing to pray to Roman gods, Christians rejected the Roman race and the Roman order of things. But Christianity posed an even greater threat than this. After decades of crisis, the ‘peace of the gods’, the unwritten contract by which the Roman gods presided benevolently over the empire in return for worship, was more than a highly guarded prize. On it depended the stability of the entire empire. It was essential to rebuilding security. Loyalty to a Christian God only put that security in jeopardy. Times of greatest crisis entailed the greatest clampdowns.
The first empire-wide persecution of Christians took place in 250. With the northern borders of the empire threatened by Goths, the emperor Decius called for a universal sacrifice in his honour. He wanted to assure himself of divine protection by the gods. Certificates of sacrifice were issued to every citizen, proving that they had participated in them. The Christians who refused were punished with torture and execution. The persecutions ended, but the problem did not. Forty years later, under Diocletian’s uniform regime of the four emperors, Roman control of belief was even more paramount. Tradition, discipline and respect for the old gods were the very cornerstones of Diocletian’s reforms and the empire’s renewal. There was no room for dissent. Unsurprisingly, it was only a matter of time before the tinder was lit and the problem of the Christians flared up violently once again.
In 299 Diocletian learnt of some pagan priests who had tried to divine signs of favour from the gods. When they were unable to find auspicious omens, they blamed their failure on some Christian soldiers who had made a sign of the cross. The reaction that resulted was uncompromising. Diocletian first ordered a purge of the army. After trying to root out Christianity he changed tack and attempted to stop it functioning altogether. He instructed a detachment of the Praetorian Guard in his own imperial city of Nicomedia not simply to burn the local church. Once the flames had subsided, he ordered his soldiers to set to work with axes and crowbars and level it to the ground.
An empire-wide edict followed: Christian meeting-places should be destroyed, scriptures burnt and Christians who held any office should be stripped of it. Depriving Christians of their status deprived them of their legal standing. They were thus liable to summary execution and torture. Christian freedmen were to be made slaves once more. Finally, the bishop of Nicomedia was beheaded and many others were imprisoned and tortured. By ruining Christianity, the persecutors were seeking to foster their traditional religion. In reality, however, the policy had no popular support. It served only to confirm how widespread Christianity had become, and how organized. The campaign had been a bloody, violent failure in an otherwise extraordinarily successful rule.8 Two years after their initiation, Diocletian called an end to the persecutions in 305.
In that same year Diocletian retired to his magnificent seaside palace at Spalatum (modern-day Split in Croatia), the skeleton of which is preserved today in the form of a medieval town. He was the first and only Roman emperor ever to abdicate voluntarily. His severe, authoritarian work of reform was done, and now he could enjoy the delights of the Dalmatian coast without worry. That at least was his hope. However, with his retirement, the success of the tetrarchy that he had devised began to decline.
Diocletian’s ambition was for the system not only to address the problem of security, but also to bring the destabilizing rapid turnover of emperors to an end. The appointment of two Caesars subordinate to two Augusti had made explicit and orderly the means of succession, and thus, it was hoped, would deter usurpers. For all the innovation and success of his other reforms, however, in this ambition his system was a complete failure. All it created was more intense jockeying for power, a new welter of rivalry and competition. It soon became apparent that the only thing that glued the four emperors together was the consent of the others. As soon as that was lost, the government of four would collapse like a sheaf of wheat.9
On 1 May 305, at the ceremonies of succession, the cracks were quick to appear. When the former Caesars, Constantius and Galerius, became the new Augusti and took the place of Maximian and Diocletian, one young man at the ceremony in the east had high hopes that he would be appointed as one of the new Caesars. However, it was not the name of Constantine, the son of Constantius, that Diocletian read out, but that of the newly appointed junior emperor Maximinus Daia, a tough, vehemently anti-Christian soldier from Illyria. The overlooked young Constantine had every right to seethe. Not only the son of a Caesar, he was also a man of considerable achievement in his own right. He had proved himself on the battlefield against the Persians on the eastern frontier, and in the north against the Sarmatians. After his father had been sent to Gaul and Britain, he had remained at Diocletian’s court. Here he was a high-ranking officer, but his achievement went further than that. In the snake-pit of politics and court life he had perhaps also learnt to be a clever dissimulator. That skill certainly would have been useful at the succession ceremony. However, he was not the only candidate to be unfairly overlooked.
At the western court in Milan, the same ceremony to appoint the new Caesar of the west was being held on the same day. Here Marcus Aurelius Valerius Maxentius, the son of Maximian, Augustus of the west, was passed over in favour of another able army officer called Flavius Valerius Severus. Maxentius had reason to be more than bitter at failing to make the grade. The appointment of Daia in the east had been understandable: he had connections there and was a trusted general and friend of Galerius. But as the son of Maximian, a former Augustus, surely Maxentius had a better claim than Severus to be Caesar in the west? Disappointment turned to suspicion. Severus, like Daia, was an army friend of Galerius. Did his appointment reflect something more sinister? Did the eastern Augustus have designs for control of the west too? The new appointment posed only unanswerable questions. Although the ambitious Constantine and Maxentius did not yet know it, opportunities would come their way to redress the slight they had suffered, and they would not be long in coming. The system of the tetrarchy would soon find itself in meltdown.
According to some sources, the first rift was between the two new Augusti. Constantius perhaps feared that his son would become a political hostage in the court of the eastern Augustus. What is certain is that he sent a dispatch to Galerius requesting that Constantine be allowed to join his campaigns to re-establish Roman order in Gaul and Britain. Galerius was reluctant to do so. Perhaps he also knew that he had a hold over his fellow Augustus as long as Constantius’s son was at his court in the east. Following persistent requests, Galerius relented, keeping up the appearance of harmony between the two senior rulers. However, beneath the show of cooperation, so the story goes, he had begun planning Constantine’s downfall. Galerius had instructed Severus to intercept and kill the young Constantine. A trap had been set.
Constantine quickly got wind of the plot. One night, he waited until Galerius had retired to his rooms. Then, in the small hours, he took flight. During the long journey west, he skilfully outwitted his pursuers by maiming horses, used for imperial service, which he encountered along the way. Constantine thus threw the potential assassins off the scent of his trail. He was a tall, strong, athletic man and, riding long and hard, he reached his father at Boulogne in Gaul in time to aid him in his last campaign – an expedition across the English Channel to Britain.10
The war against the Picts was a great success, and Constantine’s role in it was critical. For his valour he earned the title Britannicus Maximus (Greatest Briton). The popularity he gained with the army in Britain would prove incredibly influential to his future career. But perhaps equally influential was what he was able to witness. His father was a very different emperor from the eastern rulers, Diocletian and Galerius. Certainly, Constantius had paid lip-service to Diocletian’s edict to persecute the Christians; he had, for example, ordered the destructi
on of some churches. It was not in this action, however that his reputation was anchored. Rather, he was celebrated for protecting the Christians from the brutality that he had witnessed in the east. This was not out of the kindness of his heart; Constantius was a seasoned, unsentimental general from Illyria. The decision came down to a simple political judgement – he saw that persecuting Christians would not help him govern western Europe.
Unfortunately for his son, the reunion they enjoyed was brief. On 25 July 306 Constantius died prematurely at Eburacum (modern-day York). The cause of death was perhaps leukaemia, a possible clue lying in the nickname that was given to him posthumously: ‘the Pale’. There was one last, critical action that Constantius took before he died. According to Constantine, his father appointed him Augustus of the west. It was a controversial decision because Constantius had made no attempt to consult with his fellow emperors, least of all Galerius. Nonetheless, the army immediately and joyfully joined in proclaiming the popular Constantine the new Augustus of the west. With that, Diocletian’s tetrarchy was, in effect, wrecked. Constantine had broken cover.
Although Galerius, the Augustus in the east, was forced to accept Constantine’s elevation in the world, he sent him a purple robe recognizing him not as the new Augustus but as the more junior Caesar. To the position of Augustus in the west he promoted Severus. However, not even Constantine’s demotion could hide the new reality of the Roman empire. The government of the tetrarchy was nothing more than a temporary gloss. The four emperors were actually involved in a covert war, each in a bid for more power. Over the next six years that hidden war intermittently broke out into full civil war. The overlooked Maxentius was the first to make his move. He brought his father, Maximian, out of retirement, won over the Praetorian Guard in Rome and in 307 declared himself Augustus with control of Rome, Italy, Corsica, Sardinia, Sicily and North Africa. Galerius sent Severus to deal with the revolt, but Severus was unable to match the combined military forces of Maxentius and Maximian. What troops he could muster deserted him at the gates of Rome. Severus was captured, forced to abdicate power, and then executed at Tres Tabernae, outside Rome, in 307.
