Administrative Reformation by Diocletian


When Diocles, a military commander of the cavalry and leader of Numerian’s personal guard, was proclaimed emperor after his predecessor’s sudden death and renamed Diocletian, he received an empire in the verge of disaster. The administrative system that had been established by Octavian Augustus was based in the collaboration between the emperor and the senate.1 However, it had proved unable to be put to practice after Caracalla’s edict (Constitutio Antoniniana), which granted Roman citizenship to all free people of the Empire. Conflicts and civil strife hightened, as the senators rightly felt pushed aside, even in military administration, by a Νew Order of professional state employees; they belonged to lower levels of the society, but had received better education. People’s living conditions worsened dramatically during this crisis; many provinces resembled battle fields, while in others the prices of products kepts increasing, due to the devaluation of coins.

Diocletian quickly realised that he needed to reorganise the administrative system, providing solutions to problems such as the division of power, as well as the economic downfall of the Empire, leaving behind Augustus’ outdated financial and administrative system.

2. Administrative remorms

2.1. Tetrarchy

Probably Diocletian’s first act was to separate military and political power, an action that was only completed after his death, during the reign of Constantine. In the traditional roman state, administrative duties fell under the jurisdiction of military officials. Diocletian gradually separated military administration, exerted by the duces, from civil offices, which were the responsibility of a specially formed and trained class, the iudices. His final goal was to improve the Empire’s defence, and that required a more effective administration system, which would facilitate the collection of taxes and the replenishment of the army. He based his system in the concept of the division of power and official responsibilities, even applying this system to the highest power: Instead of remaining sole emperor, he kept the eastern provinces for himself, while making Maximian co-emperor and giving him the control of the western part of the empire.

Soon afterward, in 293, the two emperors appointed two praetorian prefects as caesars, thus making them their assistants and heirs: Maximian appointed Constantius Chlorus, while Diocletian appointed Galerius. The four rulers were in charge of the military administration of the provinces, based in their new imperial seats, where they built their palaces: Maximian in Augusta Treverorum (mod. Trier), Diocletian in Nicomedia, Galerius in Thessalonike and Constantius in Milan. Each had their own guard and officials. However, only the two co-emperors could issue edicts, mentioning also their caesars’ names.

2.2. Administrative restructure – Division of provinces

The provinces of the Empire were divided into smaller ones and their governors answered directly to the emperor. They were the members of a professional class of state employees, specially trained and educated for their position and part of the court bureaucracy and hierarchy; they practically formed a new social class.

Each of the old provinces was divided into two parts: an external or border part, which was heavily guarded by the army, and the inner part, which was protected by the external but also had the obligation to replenish the soldiers’ supplies. Fully aware of the problems that could arise from the increased number of provinces, Diocletian introduced an organisation based in administrative units, the dioceses; they were twelve in total: the diocese of the East, Asia, Pontos, Thrace, Moisia, Pannonia, Italy, Gaul, Vienna, Britain, Spain and Africa, each of them including several provinces.2 A new official was assigned the government of these dioceses, the vicarius, from the equestrian order.

The most significant renovation took place in Italy, which was transformed into a diocese, with twelve provinces and Milan as a seat; thus it lost its privilege to avoid taxation, because it was the administrative centre of the Empire.3 The city of Rome and its immediate environs retained this privilege (since they did not produce any agricultural products), but Rome was no longer the centre of the Empire. A full reform of the role of the governors of these dioceses also followed, as Diocletian believed that they should uphold the law and have a large number of responsibilities, but not much space to improvise. The vicarioi of the dioceses and the law itself greatly limited the governors’ powers. Their main duty was military administration, but they were also in charge of supervising each town’s boule, of conducting trials for civil matters, reviewing applications, battling crime, restoring the roads, public buildings and ports, running the postal service and collecting the province’s taxes; the last duty previously belonged to the procuratores.

These measures reorganised the whole empire, but also intented to push aside the senators, who were gradually being stripped from their jurisdiction; their former privileges were now given to officials of lower origins, especially from the equestrian order. The latters had entered court bureaucracy and hierarchy, viewing them as the only means for social advancement, and desired to preserve this system.

3. Economic reforms

Diocletian introduced a closed and controlled administrative system, which could only succeed if the economic base of the Empire was also controlled and the replenishment of army supplies was guaranteed. Therefore, he proceeded to an economic reform of the Empire.

3.1. Cencus

During the period 296-297, Diocletian ordered a systematic inventory of land, cultivated areas, animals, people and productive sources of the Empire, aiming to control these sources. He was the first emperor with a clear understanding of economic issues, connecting the cultivated land with the people who lived and worked in it, thus managing to calculate the productivity of the area. His new taxations system was based on two basic taxes: the capitatio4was a tax based on heads, which included all the people of the Empire and was paid in money or kind, according to the state’s needs; the jugatio5 was the taxation of agricultural production, which replaced an older land tax. Its difference lay on the fact that it the sum of the tax did not apply only to the extent of the land, but also to the quality of the soil and the type of the cultivated product.6 There were also smaller scale taxes on commercial production, trade products, exports and imports.

3.2 Taxation system

Diocletianos did not aim to reduce taxation or remove the annona, the taxation in kind, which covered the needs of the army; he aspired to distribute the burden of taxation with logic and consistency, balancing out the injustices of the previous periods. Each September, the state issued a financial plan according to its needs, the indictio; it was announced to the vicarii of the dioceses and they, in turn, announced it to the provinces. Then, the governors of the provinces collected the necessary funds, according to the lists, and presented them to the state in three instalments. The state retained the right to issue a supplementary financial plan (superindictio)if the need arose.

The weak point of this system lay on the fact that the collection of taxes and the necessary sum fell under the jurisdiction of the curiales and the higher class of a town, who were often held responsible and faced legal charges, or were forced to collaborate with the people, withholding evidence, in order to be able to procure the necessary funds. State finances suffered greatly from this practice, since the initial calculations for the taxes were proved unrealistic, not having taken into account the human factor and the will to avoid taxation. Administrative institutions in the cities also suffered, since their members, the ruling class, began to feel insecure and attempted to avoid public offices in local government. However, a positive aspect of this system was that payment was accepted either in money or in kind, according to the Empire’s needs; this greatly helped economy recover from the devaluation of the coin at a much quicker rate.

3.3. Measures against inflation

The emperor greatly cared for price control, issuing an edict (Edictum de maximis pretiis), which aimed to control the unreasonable inflation in the prices of products. It was a very detailed and thorough edict, which was publicly posted in all the cities of the Empire: it set firm limits on the prices of products as well as the salaries.7

3.4. Numismatic and social changes

Diocletian also attempted to control inflation by issuing new coins. He increased the gold content in the gold coins (from 70-72 gold per roman pound to 60 per roman pound), at the same time issuing a new coin called multiplus. The previous silver coin, the antoninianus, was replaced with a solid silver coin, the denarius; the denarii were already in existence, but they had lost their original value (approximately 96 coins per pound). However, the most important aspect of the reform was the introduction of a new copper coin, called follis. A follis weighed approximately 10 grams. Another radical aspect of the reform was that the coins were now issued by all ‘state’ mints, making this the first attempt for the issuing of a common state coin for the whole of the empire. These transformations in the coin system took place toward the end of the 280s until the middle of the 290s.8

Finally, Diocletian put an end to people often moving from place to place and constantly changing profession; this reform stemmed from economic motives, but soon had an important social impact. People started entering professions that they kept for life, sometimes even passed on to their children, while peasants were bonded to the land they were cultivating. It was the foundation of the medieval economic and social structures, characterised by traders’ and merchangt’s guild and by the increasing attachment of farmers to a particular piece of land.9

4. Evaluation of Diocletian’s reforms: The beginning of medieval society

Diocletian’s reforms affected the Empire as a whole: Administrative restructuring set the premises for the later medieval and modern states. The tetrarchy was an administrative experiment which facilitated in the Empire’s defence. It proved successful as long as Diocletian himself held the highest power. After his retirement, however, dynastic strife began again in the Empire, mainly due to the ambition of the son of Constantius Chlorus; he destroyed the system of the tetrarchy and reintroduced monarchy, founding the dynasty of the Neo-flavii. On the level of everyday life, the restrictions imposed on moving to a different place and changing professions contributed to the creation of feudal medieval society. Diocletian’s attempts against inflation, such as the edict concerning product prices, brought about positive results. Diocletian’s opponents, such as the rhetor Lactantius, rejected the edict, claiming that it brought the opposite results, emptying the markets. However, the numismatic reforms and the acceptance of taxes both in kind and money helped the economy survive for many centuries. The issuing of a common coin helped in bettering the image of the common, unified state that Diocletian aspired to create.

1. According to this system provinces were of two types: imperial, where officials were appointed by the emperor and he received the revenues, and senatorial, where the officials came from the class of senators. In all the provinces, the procuratores, members of the equestrial order, reported directly to the emperor.

2. Up to a point, especially in the European territories, these dioceses correspond to the modern European countries.

3. It was at that time when the division of Italy began, a division that continued throughout the Middle Ages and the Renaissance. Italy was reunited only in 1861.

4. For further information see NPauly (1997), pp. 970-971, s.v. “Capitatio-iugatio, Verfahren zur Ermittlung der Steuerlast” (E. Pack), and NPauly (1997), pp. 970-972, s.v. “Capitatio, die Kopfsteuer der späten römischen Kaiserzeit” and “Kapitatio, der Kopfsteuer der späten Kaiserzeit” (G. Schiemann). The calculating unit for the capitatio was the caput. Each adult man within a family counted as one caput, each woman as half, while slaves as well as visitors counted toward the final sum. People over 65 years of age were exempt from this tax. A very poor household could join another in order to form one caput, while wealthier capitals included a larger number of capita. See Williams, S., Diocletian and the Roman Recovery (New York – London 1996), p. 110. However, local traditions required differentiations according to regionl; in Dalmatia women were counted as one full caput, while in Egypt they were not included in the household.

5. For further information see NPauly (1997), pp. 970-971, s.v. “Capitatio-iugatio, Verfahren zur Ermittlung der Steuerlast” (E. Pack).

6. The work jugatio derives from jugerum, which measured land area and corresponded to 1/8 of an acre. The measuring unit, under Diocletian, was the jugum, which measured land in connection to the quality of the soil and the type of production. In Syria, a jugum corresponded to 5 jugera of vineyards, 20 jugera of fertle land, 40 or 60 jugera of less fertile land and 450 perticae of low production olive groves or 225 perticae of high production olive groves.

7. The edict of 301 was the first public document attempting to make prices the same for the whole empire. Similar edicts had been issued by previous emperors, such as Hadrian, but the mostly had a more limited and local nature. For more information on the edict see Frank, T., An Economic Survey of Ancient Rome (Baltimore 1940)· Michell, H., "The Edict of Diocletian: A Study of Price Fixing in the Roman Empire", Canadian Journal of Economics and Political Science (1947, reprent.)· Giacchero, M., Edictum Diocletiani ei collegarum de pretiis rerum venalium (Genoa 1974).

8. For the coins of Diocletian see Cahn, H.A., Monnaies de l’epoque de Diocletien (Bale 1954)· Depeyrot, G., Le Bas-Empire romain: economie et numismatique (Collection des Hesperides, Paris 1987). A very well founded study on the gold coins, as well as the historical background, can be found in Lukanc, I., Diocletianus: der römische Kaiser aus Dalmatien (Wetteren 1991).

9. The term ‘feudal system’ or ‘feudalism’ cannot be really applied in this case. It is being used for Western Europe but it is not always acceptable by the scholars studying Byzantium and other eastern organisation forms. The main difference lies on the landowner’s power over his subjects; this power was much larger in the west than in the east, where the peasants still retained some financial and administrative independence.