Diocletian, Latin in full Gaius Aurelius Valerius Diocletianus, original name Diocles, (born 245 CE, Salonae?, Dalmatia [now Solin, Croatia]—died 316, Salonae), Roman emperor (284–305 CE) who restored efficient government to the empire after the near anarchy of the 3rd century. His reorganization of the fiscal, administrative, and military machinery of the empire laid the foundation for the Byzantine Empire in the East and temporarily shored up the decaying empire in the West. The last major persecution of Christians occurred during his reign.
Diocletian’s biography has been obscured by legends, rhetoric, the dubiousness of documents, and the hostility of his adversaries. Little is known of his origins. His father was a scribe or the emancipated slave of a senator called Anullinus. Diocletian’s complete name, found in official inscriptions, is given as Gaius Aurelius Valerius Diocletianus. He received the name Diocles first, then the name Valerius, after the name of his daughter, Valeria, who married Galerius in 293. The gens name Aurelius did not appear until March 1, 286—that is, until after his accession. Nothing is known of his wife, Prisca, other than what the contemporary Latin Christian writer Lactantius Firmianus says in his De mortibus persecutorum, which is of debatable veracity. Diocles, having adopted the name Diocletianus, entered history like so many of those emperors who emerged from the shadows through force of arms, brought to power by the army. What is known of his appearance is based on coin effigies and on sculptures. From these it appears that he was tall and thin, with a large forehead, a short, strong nose, a hard mouth, and a determined chin.
Rise to power
Up to the time of his accession, Diocletian had lived most of his life in military camps. These may have been either in Gaul, as reported in the Historia Augusta, or in Moesia. Or he may have been a member of the Roman emperor Carinus’s bodyguard. The only definite fact known about Diocletian during this period is that he was among those army chiefs whom Carinus gathered, together with the Illyrians, to fight against the Persians. In 284, during that campaign, Numerian, Carinus’s brother and coemperor, was found dead in his litter, and his adoptive father, the praetorian prefect Aper, was accused of having killed him in order to seize power. When Diocletian, acclaimed as emperor by his soldiers, appeared for the first time in public dressed in the imperial purple, he declared himself innocent of Numerian’s murder. He designated Aper as the criminal and killed him personally. Here again, rhetoric has obscured the real events. Aper’s guilt was accepted by contemporaries, but it was also true that a prediction had been made to Diocletian previously, telling him that he would become emperor on the day he killed a boar (Latin: aper). And it was true, too, that he did not wish to wait much longer for the boar to come. In reality, Numerian had died either a natural death or from a stroke of lightning. With the death of Aper, however, Diocletian was relieved of an eventual competitor and, retroactively, his act had been granted sacred meaning.
Acclaimed emperor on 17 November 284, Diocletian possessed real power only in those countries that were dominated by his army (i.e., in Asia Minor and possibly Syria). The rest of the empire was obedient to Numerian’s brother Carinus. After having put down a revolt by Julianus, a troop commander in Pannonia, whom he attacked and killed near Verona, Carinus proceeded to attack Diocletian. An indecisive battle near the confluence of the Margus (modern Morava) and Danube rivers, not far from present-day Belgrade, would have been a defeat for Diocletian had Carinus not been assassinated by a group of soldiers. Thus, in midsummer of 285, Diocletian became master of the empire.
Reorganization of the empire of Diocletian
At the beginning of 286, Diocletian was in Nicomedia. In the interim, he and his lieutenants had calmed the stirrings of revolt among Roman troops stationed on the frontiers. From that point on, he dedicated himself to restoring civil order to the empire by removing the army from politics.
Although he came from the army’s ranks, Diocletian was not, properly speaking, a soldier. He had scarcely come to power when he made an unexpected decision—to share the throne with a colleague of his choice. The empire was too great for one man to administer; nearly every week, either in Africa, or somewhere on the frontier that extended from Britain to the Persian Gulf, along the Rhine, the Danube, the Pontus Euxinus (Black Sea), and the Euphrates, he was forced to suppress a revolt or stop an invasion. Diocletian, who was more attracted to administration, required a man who was both a soldier and a faithful companion to take responsibility for military defense. In 286 he chose Maximian, an Illyrian, the son of a peasant from the area around Sirmium. A little later, though still keeping Rome as the official capital, he chose two other residences. Maximian, who was responsible for the West, was installed at Milan in northern Italy, in order to prevent German invasions. Diocletian established himself at Nicomedia, in western Anatolia and close to the Persian frontier, in order to keep watch on the East. Six years later, in 293, having taken the title of “Augustus” and given it to Maximian as well, he added two more colleagues: Galerius, a former herdsman, and Constantius I Chlorus, a Dardanian nobleman according to the legend of his house, but a rather rude countryman also. These additional collaborators were each given the title “Caesar” and attached to an Augustus, Constantius to Maximian (with a residence in Trier), and Galerius to Diocletian himself (with a residence in Sirmium).
Thus, while the empire remained a patrimonium indivisum (undivided inheritance), it was nevertheless divided administratively: Diocletian, residing in Nicomedia, watched over Thrace, Asia, and Egypt; Galerius, residing in Sirmium, watched over Illyria, the Danubian provinces, and Achaea; Maximian, residing in Milan, over Italy, Sicily, and Africa; and Constantius I Chlorus, residing in Trier, over Gaul, Spain, and Britain. In order to strengthen the union of the colleagues, each Augustus adopted his Caesar. The relationships were further cemented when Galerius married Valeria, Diocletian’s daughter, and Constantius I Chlorus repudiated his wife (or concubine) Helena, mother of the future emperor Constantine I, in order to marry Theodora, Maximian’s stepdaughter. The empire now had four masters, celebrated by the authors of the Historia Augusta (a collection of biographies of Roman emperors and caesars, published in the 17th century) as the quattuor principes mundi (“four princes of the world”), and Diocletian consecrated this human unity by forming a religious bond. Because he believed that he had come to power through divine will, as revealed by the “fateful” boar, he regarded himself and Maximian as “sons of gods and creators of gods.” After 287 he called himself Jovius (Jove) and Maximian was named Herculius (Hercules), signifying that they had been chosen by the gods and predestined as participants in the divine nature. Thus, they were charged with distributing the benefits of Providence, Diocletian through divine wisdom, and Maximian through heroic energy. Later designated as dominus et deus on coins and inscriptions, Diocletian surrounded himself with pomp and ceremony and regularly manifested his autocratic will. Under Diocletian, the empire took on the aspects of a theocracy.
Diocletian’s reforms were successful; they put an end to domestic anarchy, and elsewhere they allowed Maximian to defeat the revolt in Gaul of the Bagaudae, bands of peasants who found the tribute oppressive. Then, with peace scarcely restored after a campaign against the Germans, Maximian had to battle Carausius, who, having fought for the empire in Britain against the Frankish and Saxon pirates, revolted and named himself emperor in Britain in 287. Carausius reigned in Britain for nearly 10 years until Constantius I Chlorus succeeded in returning Britain to the empire in 296. Scarcely had troubles in Mauretania and in the Danubian regions been settled when Egypt declared itself independent under the usurper Achilleus. Diocletian reconquered the country in 296. Finally, in 297, he had to fight Narses, king of Persia, who had invaded Syria. Since he was still occupied in Egypt, he assigned this operation to Galerius, who, after a protracted campaign, finally won victory for the Romans. Tiridates, the king of Armenia and a protégé of the Romans, was able to return to his throne; the Tigris became the eastern border of the empire; and peace reigned in that part of the world until the reign of Constantine I (306–337).
Written by: Mandy Law