Diocletinus, Gaius Valerius Iovius
A celebrated Roman emperor, born of an obscure family in Dalmatia at the town of Dioclea, from which he derived his first name, which was probably Docles, afterwards lengthened to the more harmonious Greek form of Diocles, and at length, after his accession to the Empire, to the Roman form of Diocletianus. He likewise, on this occasion, assumed the patrician name of Valerius. Some, however, make him to have been born at Salona. His birth-year is also differently given. The common account says A.D. 245, but other statements make him ten years older. He was first a common soldier, and by merit and success gradually rose to rank, serving in Gaul and in Moesia under Probus, and being present at the campaign against the Persians when Carus perished in so mysterious a manner. He commanded the household or imperial body-guard when young Numerianus, the son of Carus, was secretly put to death by Aper, his father-in-law, while travelling in a litter on account of illness, on the return of the army from Persia. The death of Numerianus being discovered, after several days, by the soldiers near Chalcedon, they arrested Aper and proclaimed Diocletian emperor, who, addressing the army from his tribunal in the camp, protested his innocence of the death of Numerianus, and then, upbraiding Aper for the crime, plunged his sword into his body. Diocletian made his solemn entry into Nicomedia in September, A.D. 284, and afterwards chose this town for his favourite residence. Carinus, the other son of Carus, having collected a force to oppose Diocletian, the two armies met at Margum in Moesia, where the soldiers of Carinus had the advantage at first, but Carinus himself having been slain by one of his own officers, both armies joined in acknowledging Diocletian emperor, A.D. 285. Diocletian was generous after his victory, and, contrary to the common practice, there were no executions, proscriptions, or confiscations of property. He even retained most of the officers of Carinus in their places. Diocletian, on assuming the imperial power, found the Empire assailed in various quarters, but his talents and energy soon succeeded in counteracting these evils. In the year 286, he chose his old friend Maximian, a brave, but rude and uncultivated soldier, as his colleague, and it is to the credit of both that the latter continued ever after faithful to Diocletian and willing to follow his advice. Maximian was stationed in Gaul, and on the German frontier, to repel invasion; Diocletian resided chiefly in the East, to watch the Persians, though he appears to have visited Rome in the early part of his reign. After the lapse of a few years Diocletian thought it necessary, in consequence of invasions and revolts in different parts of the Empire, to increase the number of his colleagues. On the 1st of March, 292, or, according to some, 291, he appointed Galerius a Caesar, and Maximian, at the same time, adopted, on his part, [figure in text: Coin of Diocletian.] Constantius Chlorus. The two Caesars repudiated their respective wives; Galerius married Valeria, Diocletian's daughter, and Constantius married Theodora, daughter of Maximian. The two Caesars remained subordinate to the two Augusti, though each of the four was intrusted with the administration of a part of the Empire. Diocletian kept to himself Asia and Egypt; Maximian had Italy and Africa; Galerius, Thrace and Illyricum; and Constantius, Gaul and Spain. But it was rather an administrative than a political division. At the head of the edicts of each prince were put the names of all four, beginning with that of Diocletian. Diocletian resorted to this arrangement probably as much for reasons of internal as of external policy. By fixing upon three colleagues, one in each of the great divisions of the Empire, each having his army, and all mutually checking one another, Diocletian put a stop to military insolence and anarchy, though another danger remainedthat of disputes and wars between the various sharers of the imperial power.
The new Caesars justified Diocletian's expectations. Successful wars were waged in different quarters of the Empire; and though Galerius at first met with a defeat from Narses, king of Persia, yet, in the following year, he gave the Persians a terrible overthrow. Narses sued for peace, which was granted by Diocletian, on condition of the Persians giving up all the territory on the right or western bank of the Tigris. This peace was concluded in 297, and lasted forty years. At the same time Diocletian marched into Egypt against Achillaeus, whom he besieged in Alexandria, which he took after a siege of eight months, when the usurper and his chief adherents were put to death. Diocletian is said to have behaved on this occasion with unusual sternness, several towns of Egypt, among others Busiris and Coptos, being destroyed. For several years after this the Empire enjoyed repose, and Diocletian and his colleagues were chiefly employed in framing laws and administrative regulations and in constructing forts on the frontiers. Diocletian kept a splendid court at Nicomedia, which town he embellished with numerous structures. He, or rather Maximian by his order, caused the magnificent Thermae [p. 516]
at Rome to be built, the remains of which still bear Diocletian's name, and which contained, besides the baths, a library, a museum, and other establishments.
In February, 303, Diocletian issued an edict against the Christians, ordering their churches to be razed, their books to be burned, and all Christians to be dismissed from offices civil or militarywith other penalties, exclusive, however, of death. Various causes have been assigned for this measure. It is known that Galerius had always been hostile to the Christians, while Diocletian had openly favoured them, and had employed them in his armies and about his person; and Eusebius speaks of the prosperity, security, and protection which they enjoyed under his reign. They had churches in most towns, and one at Nicomedia, in particular, under the very eye of the emperor. Just before the edict was issued, Galerius had repaired to Nicomedia to induce Diocletian to proscribe the Christians. He filled the emperor's mind with reports of conspiracies and seditions, and, aided by the artifices of the heathen priesthood, was at last successful. The barbarities that followed upon the issuing of the edict above referred to are beyond belief. Malicious ingenuity was racked to the utmost to devise tortures for the persecuted followers of Jesus. For the space of ten years did this persecution rage with scarcely mitigated horrors; and such multitudes were massacred in all parts of the Empire that at last the imperial murderers ventured to erect a triumphal column, bearing the barbarously boastful, yet false inscription, that they had extinguished the Christian name and superstition and restored the worship of the gods to its former purity and splendour. This was the last persecution under the Roman Empire.
In November, 303, Diocletian repaired to Rome, where he and Maximian enjoyed the honour of a triumph, followed by festive games. This was the last triumph that Rome saw. The populace of that city complained of the economy of Diocletian on that occasion, and so offended him by their gibes and sarcasms that he left Rome abruptly, in the month of December, in very cold weather. A long illness ensued, which confined him at Nicomedia; and soon after his recovery he was visited by Galerius, who persuaded and almost forced him to abdicate. According to others, however, Diocletian did so spontaneously. Setting off for Salona, in Dalmatia, he built himself, near this place, an extensive palace by the sea-shore, in which he lived for the rest of his life, respected by the other emperors, without cares and without regret. At the same time that Diocletian abdicated at Nicomedia, Maximian, according to an agreement between them, performed a similar ceremony at Milan. Maximian retired to his seat in Lucania; but, not being endowed with the firmness of Diocletian, he tried some time after to recover his former power, and wrote to his old colleague to induce him to do the same. Were you but to come to Salona, answered Diocletian, and see the vegetables which I raise in my garden with my own hands, you would no longer talk to me of empire. Diocletian died May 1, 313. See the studies by Preuss (1868) and Mason (1876).