Diocletian

Roman emperor (r. 284/285-305 c.e.)

• Born: c. 245
• Birthplace: Possibly Salonae, Dalmatia (now Solin, Croatia)
• Died: December 3, 0316
• Place of death: Salonae, Dalmatia (now Solin, Croatia)

Diocletian put an end to the disastrous phase of Roman history known as the Military Anarchy or the Imperial Crisis and laid the foundation for the later Eastern Roman Empire, known as the Byzantine Empire. His reforms ensured the continuity of the Empire in the East for more than a thousand years to follow.

Early Life

Little is known for certain about the early life of Diocletian (di-uh-KLEE-shuhn). He was a native of the Dalmatian coast, was of very humble birth, and was originally named Diocles. He was either the son of a freedman or a slave by birth who was later set free. His father may have been a scribe. He grew up in the household of the senator Anullinus, and it is unlikely that he received much education beyond the elementary literacy he may have learned from his father. The scanty evidence suggests that he was deeply imbued with religious piety. Later coin portraits give an impression of his appearance: They show a close-cropped beard in the contemporary Illyrian style, a wide forehead, and eyes spaced far apart. He had a wife, Prisca, and a daughter, Valeria, both of whom reputedly were Christians.

During Diocletian’s early life, the Roman Empire was in the midst of turmoil. In the early years of the third century, emperors who were increasingly insecure on their thrones had granted inflationary pay raises to the soldiers. The additional costs could be met only by debasing the silver coinage, which soon became worthless, causing the ruin of the Roman economy. The only meaningful income the soldiers then received was in the form of gold donatives granted by other leaders. This practice served to encourage emperor-making. Beginning in 235, armies throughout the Empire began to set up their generals as rival emperors.

The resultant civil wars opened up the Empire to invasion in both the north, by the Franks, Alemanni, and Goths, and the east, by the Sāsānian Persians. Another reason for the unrest in the army was the great gap between the social backgrounds of the common soldiers, who were recruited from the more backward provinces of the Empire, such as Illyria, and the officer corps, made up largely of cultured senators. As of the 250’s, however, this situation began to change. Many legionnaires made their way to high rank. Beginning in 268, some even were acclaimed emperors themselves. These individuals, the so-called Illyrian or soldier emperors, gradually were able to bring the army back under control, even though their newfound status aroused enmity against them from the senators.

Like many of his countrymen, Diocletian sought his fortune in the army. He showed himself to be a shrewd, able, and ambitious individual. He soon rose to high rank. He is first attested as duke of Moesia (an area on the banks of the lower Danube River), with responsibility for border defense. He was a prudent and methodical officer, a seeker of victory rather than glory. In 282, the legions of the upper Danube proclaimed the praetorian prefect Carus emperor. Diocletian found favor under the new emperor and was promoted to count of the domestics, the commander of the cavalry arm of the Imperial bodyguard. In 283 he was granted the honor of a consulate.

In 283, in the midst of a campaign against the Persians, Carus was killed, struck by a bolt of lightning that one writer noted might have been forged in a legionary armory. That left the Empire in the hands of his two young sons, Numerian in the east and Carinus in the west. Soon thereafter, Numerian died under mysterious circumstances near Nicomedia, and Diocletian—who had by this time changed his name from Diocles to Diocletian—was acclaimed emperor in his place. In 285, Carinus was killed in a battle near Belgrade, and Diocletian gained control of the entire empire.

Life’s Work

As emperor, Diocletian was faced with many problems. His most immediate concerns were to bring the mutinous and increasingly barbarized Roman armies back under control and to make the frontiers once again secure from invasion. His long-term goals were to restore effective government and economic prosperity to the Empire. Diocletian concluded that stern measures were necessary if these objectives were to be met. More than earlier emperors, he believed that it was the responsibility of the Imperial government to take whatever steps were necessary, no matter how harsh or unorthodox, to bring the Empire back under control. Earlier emperors, with typical Roman conservatism, had attempted to apply the methods instituted by Emperor Augustus (r. 27 b.c.e.-14 c.e.), even those no longer appropriate for the times. Diocletian believed that contemporary needs required him to abandon the Augustan “Principate” and to strike out on his own.

Diocletian was able to bring the army back under control by making several changes. He subdivided the roughly fifty existing provinces into approximately one hundred, thereby putting less authority into the hands of each governor. The provinces also were apportioned among twelve dioceses, each under a vicar, and later also among four prefectures, each under a praetorian prefect. As a result, the Imperial bureaucracy became increasingly bloated. He institutionalized the policy of separating civil and military careers, so that provincial governors would not also be the commanders of armies. He divided the army itself into so-called border troops, actually an ineffective citizen militia, and palace troops, the real field army, which often were led by the emperor in person.

Following the precedent of Emperor Aurelian (r. 270-275), Diocletian transformed the emperorship into an out-and-out oriental monarchy. The emperor now became a truly august, godlike figure, removed from the rest of society. He wore gold and purple robes and a pearl diadem. Access to him became restricted; he now was addressed not as “princeps” (first citizen) or the soldierly “imperator” (general), but as “dominus noster” (lord and master). Those in audience were required to prostrate themselves on the ground before him.

Diocletian also concluded that the Empire was too large and complex to be ruled by only a single emperor. Therefore, in order to provide an Imperial presence throughout the Empire, he introduced the Tetrarchy, or Rule by Four. In 285, he named his lieutenant Maximian “caesar,” or “junior emperor,” and assigned him the western half of the Empire. This practice began the process that would culminate with the de facto split of the Empire in 395. Both Diocletian and Maximian adopted divine attributes. Diocletian was identified with Jupiter and Maximian with Hercules. In 286, Diocletian promoted Maximian to the rank of augustus, “senior emperor,” and in 293 he appointed two new caesars, Constantius (the father of Constantine I, the Great), who was given Gaul and Britain in the west, and Galerius, who was assigned the Balkans in the east.

By instituting his Tetrarchy, Diocletian also hoped to solve another problem. In the Augustan Principate, there had been no constitutional method for choosing new emperors. The result of this, especially in the third century, had been civil wars when different armies named their own generals as the next emperor. According to Diocletian’s plan, the successor of each augustus would be the respective caesar, who then would name a new caesar. Initially, the Tetrarchy operated smoothly and effectively. Even though Diocletian and Maximian technically were of equal rank, it always was clear that Diocletian really was in charge.

Once the army was under control, Diocletian turned his attention to other problems. The borders were restored and strengthened. In the early years of his reign, Diocletian and his subordinates were able to defeat foreign enemies such as Alemanni, Sarmatians, Saracens, Franks, and Persians, and to put down rebellions in Britain and Egypt. The eastern frontier was actually expanded.

The economy remained in a sorry state. The coinage had become so debased as to be virtually worthless. Diocletian’s attempt to reissue good gold and silver coins failed because there simply was not enough gold and silver available to restore confidence in the currency. A Maximum Price Edict issued in 301, intended to curb inflation, served only to drive goods onto the black market. Diocletian finally accepted the ruin of the money economy and revised the tax system so that it was based on payments in kind (the annona) rather than in the now-worthless money. The annona came to be recalculated in periodic reassessments (indications) every fifteen years. The soldiers, too, came to be paid in kind. Their only salary of value eventually became donatives issued at five-year intervals in gold and silver.

In order to assure the long-term survival of the Empire, Diocletian identified certain occupations that he believed would have to be performed. These were known as the compulsory services. They included such occupations as soldiers, bakers, members of town councils (the decurions), and tenant farmers (the coloni, who evolved into the serfs of the Middle Ages). These functions became hereditary, and those engaging in them were inhibited from changing their careers. The repetitious nature of these laws, however, suggests that they were not widely obeyed. Diocletian also expanded the policy of third century emperors of restricting the entry of senators into high-ranking governmental posts, especially military ones.

Like Augustus and Decius (249-251), Diocletian attempted to use the state religion as a unifying element. Encouraged by the caesar Galerius, Diocletian in 303 issued a series of four increasingly harsh decrees designed to compel the Christians to take part in the Imperial cult, the traditional means by which allegiance was pledged to the Empire. This began the so-called Great Persecution.

On May 1, 305, wearied by his twenty years in office and determined to implement his method for the Imperial succession, Diocletian abdicated. He compelled his co-regent, Maximian, to do the same. Constantius and Galerius then became the new augusti, and two new caesars were selected, Maxentius in the east and Severus in the west. Diocletian then retired to his palace at Split on the Yugoslavian coast. In 308 he declined an offer to resume the purple, and the aged former emperor died in 316 c.e.

Significance

Diocletian recognized that the Empire as it had been established by Augustus simply did not meet the needs of his own time. He therefore instituted many administrative reforms. Not all of them, however, were completely successful. His Tetrarchy, for example, in the choice of new emperors, bypassed obvious dynastic choices. As a result, another round of civil wars swept the Empire. Constantine, the son of Constantius, emerged as the victor. Diocletian’s retention of the ineffective border troops created a great drain on the treasury, and his abandonment of the money economy meant the ruin of much of the private business in the Empire. The Great Persecution ended in failure in 311, and soon afterward Constantine the Great identified Christianity itself as a more viable unifying factor.

Diocletian’s successes, however, greatly outweighed his failures. He was much more skilled as an administrator than as a general, but an administrator was just what the Empire needed at that time. The pattern he established was maintained, and expanded, after his death. Emperors continued to claim absolute authority in all matters and to try to solve problems by legislative decree. Diocletian’s reforms brought the Empire back from the brink of extinction and laid the foundation for the Byzantine Empire.

Roman Emperors from Carus to Constantine the Great

282-283

• Carus

283-284

• Numerian (East)

283-285

• Carinus (West)

284-305

• Diocletian (East)

293-305

• Maximian (West)

305-306

• Constantius (West)

305-315

• Galerius (East)

306-307

• Severus (West)

306-312

• Maxentius (West)

306-337

• Constantine the Great (East)

308-324

• Licinius (East)

324-337

• Constantine the Great (all)

Bibliography

Arnheim, M. T. W. The Senatorial Aristocracy in the Later Roman Empire. Oxford, England: Clarendon Press, 1972. A detailed discussion of the evolution of the ruling class of the Empire under Diocletian and his successors. Uses the methodology known as “prosopography,” or “collective biography.”

Barnes, Timothy D. The New Empire of Diocletian and Constantine. Cambridge, Mass.: Harvard University Press, 1982. An investigation of the administrative restructuring of the Empire that occurred under Diocletian.

Brauer, George C. The Age of the Soldier Emperors: Imperial Rome, A.D. 244-284. Park Ridge, N.J.: Noyes Press, 1975. A clear discussion of the Illyrian emperors of the third century, culminating in the reign of Diocletian. Particular use is made of the numismatic evidence.

Brown, Peter. The World of Late Antiquity: From Marcus Aurelius to Mohammed. New York: Norton, 1989. A very broad and well-illustrated discussion of the social and cultural background of the new age that began in the later part of the third century.

Jones, Arnold H. M. The Later Roman Empire, 284-602: A Social, Economic, and Administrative Survey. Baltimore: The Johns Hopkins University Press, 1986. The standard scholarly discussion of the Roman world beginning with the restructuring that occurred during the time of Diocletian. Places Diocletian’s reforms in their broader context. Fully annotated.

Williams, Stephen. Diocletian and the Roman Recovery. New York: Routledge, 1997. A detailed, chronological biography of Diocletian. Includes an extensive bibliography of other scholarship on Diocletian as well as some illustrations.