In front of everyone he killed the murderer of his predecessor with the sword

In the third century AD, the office of Roman emperor was not necessarily a post of long life. Ambitious politicians and generals regularly had their soldiers proclaim themselves emperors, so that often enough several usurpers claimed the purple for themselves. Predecessors to these soldier emperors were quickly and brutally eliminated.

The year 284 was therefore no exception. Two years earlier, after six years in office, Probus had suffered the usual death when his soldiers renounced their loyalty to him and defected to the praetorian prefect Carus. He immediately appointed his sons Carinus and Numerianus Caesars and thus designated successors. After a victory over Quadi and Sarmatians, Carus even elevated both to Augusti and undertook a campaign against the Persian Sasanids with the younger Numerianus, which culminated in the occupation of their capital Ctesiphon (today Baghdad).

But with the success, Carus had probably exhausted his luck. In the camp on the Tigris he is said to have been struck by lightning in the summer of 293, an undoubtedly unusual death, which the ancient historian Alexander Demandt, however, considers credible with reference to similar historical cases. Without problems, the legions proclaimed the son Numerianus emperor, who successfully led the army back together with Aper, his father-in-law and commander of the Praetorian Guard.

On the way to Europe, Numerianus suddenly disappeared from the scene in the autumn of 284. In order not to provoke the soldiers into rash actions, the death was kept secret and the deceased was transported in a covered wagon. In his new biography of Emperor Diocletian, Demandt suspects that Aper wanted to buy time to make his own candidacy for the succession palatable to the legionnaires. The scanty sources offer the version that the Praetorian Prefect was not entirely innocent in the death of his son-in-law.

At some point, however, the death of the emperor could no longer be concealed. In Nicomedia (today Izmit) in Asia Minor, the officers discussed the succession. Surprisingly, they did not choose Aper or Carinus, who was staying in Gaul, but Diocletian. The assembled army delivered the acclamation, Diocletian grabbed “the purple” and waived recognition by the Senate in Rome. Since Carus, even this last relic of aristocratic co-rule had disappeared.

Diocletian was a military man through and through. This was already shown by his origins in the western Balkans, where Rome now recruited its best soldiers. His date of birth is not known, but may have been around 248. He is said to have been "absurissime natus", of the lowest origin. He may have been a freedman of a senator, so originally a slave. Although his original Greek name was Diocles, his knowledge of Greek was modest.

Diocletian, on the other hand, knew a lot about the military. He quickly worked his way up from a simple soldier to an officer. Under Carus and Numerianus he led the imperial bodyguard. There are no rumors that he himself was involved in the death of the emperor.

In contrast, Diocletian immediately put his own version into the world. Weapon in hand, he swore to the army that he was innocent of the Emperor's assassination. Instead, he killed Aper "with the sword before the eyes of the army," reports the historian Eutropius. This also had the advantage that he freed himself from his most dangerous competitor.

However, this did not eliminate the problem that the other Carus son, Augustus Carinus, was successfully waging war against the Germans with a large army. There, in the meantime, a certain Julian had risen to become the opposing emperor, but after his defeat he "stabbed his dagger in the ribs and threw himself into the fire," as one source reports.

The decisive battle between Carinus and Diocletian took place on the Morava in present-day Serbia. He looked like the winner for a long time, but was killed by his own people. The leader is said to have been a tribune whose wife is said to have been seduced by Carinus. Other sources attribute all sorts of perversions to the murdered man.

The lucky winner again gave a sample of his political talent. Instead of venting his vengeance on Carinus' high-ranking collaborators, he left them in office, renounced the damnatio memoriae (damnation of memory) of his predecessor and even the train to Rome. Because on the Danube the Sarmatians had once again advanced into imperial territory. He immediately went to meet you.

It had not been seen in generations that there was so much leniency towards the losers. It is not for nothing that the historian Aurelius Victor praised the "new and unexpected behavior, while it is gratifying if at least moderation is observed in the case of ostracism, banishment and executions".

This began a reign by the end of which, in AD 304, the Roman Empire had changed significantly. Diocletian pushed far-reaching reforms. Provinces were reduced in size and grouped into dioceses, significantly reducing the base of potential usurpers. The central authorities were tightened and expanded, the economy was reorganized, laws were codified, the army was organized into a border guard and mobile intervention troops in the rear, and the number of cavalry was significantly increased.

All this was controlled by a tetrarchy, the rule of two Augusti (senior emperors), to each of whom a Caesar was assigned. Not family ties, but experience and loyalty justified the appointment and the willingness to resign after a specified period of time. Each managed a district of the empire from one of the new residences in Milan, Trier, Nicomedia or Thessalonica, but saw themselves as responsible for the entire empire. The fact that the tetrarchs also wanted to strengthen the unity of the empire by intensifying the imperial cult sharpened their opposition to the Christians, which erupted in bloody persecutions.

That has obscured the memory of Diocletian for a long time. To the astonishment of his contemporaries, he actually resigned his office in 305 and retired to his huge palace in Spalato (Split). There he experienced how Constantine destroyed the system of the tetrarchy and elevated Christianity to a privileged religion.

This failure is offset by the achievement of “bringing inner peace to the empire for twenty years”, Alexander Demandt draws a positive balance: Diocletian’s reforms created the administrative basis for late antiquity, which was shaped by Christianity, “an invaluable achievement, since at that time the Greco-Roman cultural heritage was collected and put into the form in which the Middle Ages took it over".

Alexander Demandt: "Diocletian. Emperor of two worlds. A Biography". (C. H. Beck, Munich. 432 p., 32 euros)

You can also find "World History" on Facebook. We are happy about a like.