The half-century of Diocletian and Constantine (284-337 ce) is often presented as a period of revolution when a new empire was fashioned. During this period there was a complex series of reforms of the whole mechanism of government, but despite the undoubted importance of Diocletian and Constantine, not all developments in the third and fourth centuries should be attributed to them. Focusing on these rulers obscures the contributions of other emperors during this period. The reality of the new empire of Diocletian and Constantine was a generalized groping towards a formalization of existing practices carried out in a sporadic fashion. Understanding the changes is difficult because of the challenges presented by the sources. The source material from the mid-third century is weak and there is no connected narrative for the reign of Diocletian. This means that first attestations can easily occur some time after changes had first been introduced. A good example of this is the formation of regiments of lanciarii, sometimes attributed to Diocletian (van Berchem 1952: 107). As a result of recent archaeological work at Apamea in Syria, we now know that lanciarii existed in the early third century (Balty 1988; AE 1993 nos.1574-5). After the reign of Diocletian, the source material increases in volume, but its interpretation remains difficult thanks to Constantine’s status as first Christian emperor and victor in a series of civil wars, which affected the way in which he was described by both contemporaries and later writers (Lieu and Montserrat 1996).
On May 23, 326 Acilius Severus, the Prefect of Rome, received a law from Constantine. The emperor was in either Aquileia or Milan or on the road between the two cities. The law concerned the peculia of the palatini ‘‘who follow our standards, who always assist our actions, who, bent on their clerical duties, are exposed to lengthy journeys and difficult marches, are no strangers to the dust and toil of the camp’’ (CTh. 6.36.1). Both emperors and government were itinerant and their travels covered most of the empire. Maximian, for example, was in Aquileia in March 296, spent the summer on the Rhine, the autumn in Spain, and then crossed over to Africa where he was on campaign by the following March, if not earlier. It would be easy to confuse emperors with generals, were it not for the fact that imperial movements can often be tracked by the laws issued as the emperors moved. Late third - and fourth-century government centered on the emperor, so any analysis of the state should start there.
In theory at least, emperors existed to provide law, order, and justice for their people. While there are many different ways of thinking about the emperor, this section follows Millar’s concept of‘‘the emperor was what the emperor did’’ (Millar 1977: 6). Regardless of the perquisites of office, being Roman emperor was a demanding and often dangerous job - Maximian’s travels show the constant military pressure on the state. But ruling involved other tasks as well: hearing appeals, public appearances, etc. From Diocletian onwards, the empire was almost always run by multiple emperors, a recognition that the state was too unwieldy to be run by one man. Only a year after his accession, Diocletian began to share power with Maximian in 285 (Leadbetter 1998). From 293 he expanded the arrangement to include Constantius and Galerius in a college of four emperors known as the tetrarchy. The unity of the tetrarchy, its indivisum patrimonium (Pan. 3[11].6.3), was constantly stressed: the acts of one emperor were the acts of all four. Since the tetrarchs met only rarely (and the first tetrarchy never met as four men in the same city), this was especially important. Thus the ninth milestone from Verona was erected in the name of ‘‘Imperator Caesar C. Valerius Diocletianus Pius Felix Invictus Augustus and Imperator Caesar Marcus Aurelius Valerius Maximianus Pius Felix Invictus Augustus and Flavius Valerius Constantius and Galerius Valerius Maximianus, most noble Caesars’’ (ILS 636). There developed a distinctive iconography by which all four emperors were shown together, seen in e. g. the Venice Tetrarchs, the Arch of Galerius, and in the Temple of Ammon at Luxor (Rees 1993). Constantine carried out the same practice. An inscription from Cirta in the North African province of Numidia was dedicated by the provincial governor to ‘‘the perpetual victory of our lords Constantine Maximus, triumphator, always Augustus, and to Constantine and Constantius and Constans, most noble and flourishing Caesars’’ (ILS 715). On Diocletian’s retirement in 305, the first tetrarchy was replaced with a second tetrarchy of Constantius, Galerius, Maximinus, and Severus, though this soon fell to pieces in a series of civil wars. When the fighting was over and Constantine was dominant as sole ruler, a system of multiple rulers was re-instituted, with Constantine appointing his sons and a nephew as Caesars. The final version of this new tetrarchy involved Constantine II based in Gaul, Constantius II on the eastern frontier, Constans in Italy, Africa, and the western Balkans, and the nephew Dalmatius in the eastern Balkans. Although these large imperial colleges, confusing to both modern scholars and contemporaries, were an innovation, the idea of multiple rulers was not. The same advantages (stability of succession, ability to deploy imperially-led forces on more than one front) had been appreciated by emperors since the Flavians in the first century ce, if not before. During the third century, there were several periods of multiple emperors, whether jointly appointed (Balbinus and Pupienus), father and son (Valerian and Gallienus, or Carus, Carinus, and Numerianus), or coexisting (the central empire of Valerian and Gallienus or Aurelian, with subsidiary states in Palmyra
Figures 10.1a-d The tetrarchs: (a) Diocletian (RIC 79a); (b) Maximian (KM 1991 2.816); (c) Constantius I (RIC Constantius I n. 32a); (d) Galerius (RIC Galerius 24b) (Figures 10.1a, b, and d from the editor’s collection)
And the Gallic Empire). Diocletian’s measures were thus a rationalization of existing practices. The precise relationship of Augusti to Caesars is not well understood. All were emperors, but Augusti were clearly superior to Caesars. The 305 retirement settlement of Diocletian was the result of diktat, not negotiation, and later senior Augusti were less able to be autocratic. It seems that Caesars in the tetrarchy did not have their own administrations, but rather shared those of the Augusti. However, they did have their own courts, armies, and powers to issue laws (Corcoran 2000: 266-74). Though the cooperation of the tetrarchs and thus the success of the tetrarchic system depended on Diocletian’s will, and so disintegrated on his retirement, in the short term it provided enough stability to allow other changes to occur. Imperial deployment in 298 showed the strengths of the new system, with the tetrarchs dealing simultaneously with problems on four fronts. Constantius held the Rhine against the Franks while Maximian was still in Africa, probably fighting the Laguatan. In Syria, Galerius invaded Persia while Diocletian was in Egypt (Zucker-man 1994). Similar flexibility was provided by Constantine’s reliance on his family, recognized by Eusebius, who described Constantine’s illumination of the world through his Caesars (Euseb. LC 3.4).
The intense military pressures of the third century meant that emperors and their retinues spent most of their reigns on the frontiers, or marching along well-worn routes linking border regions. These imperial retinues, known as the comitatus (more graphically as stratopedon in Greek: literally ‘‘the camp’’), included the emperor’s household, personal attendants, cooks, barbers, etc. Many of these men were attended by their slaves. When at war, a substantial military contingent accompanied the emperor, but even when not on campaign, there were thousands of guard troops in attendance. The whole administrative machine of the empire also accompanied the emperor, allowing him to issue laws, collect taxes, hold trials, and hear appeals. Files could be consulted since court records were sent to the emperor (CTh. 1.16.3 [319]). There was also the traffic of ambassadors and messengers who were constantly arriving. The staff all needed to be fed; many of them needed their own horses or mules, and these needed to be fed too. A single receipt from Egypt for part of one unit in February 295 shows the scale of the system: ‘‘Valens, optio of Legio VII Claudia under Julianus praepositus, I have received 1740 lbs of fodder in three days from Sarmates and Didymus, curatores of the Oxyrhynchite nome’’ (P. Oxy. 43 col. 5). These supplies kept coming in an unending stream. The system allowed the emperor, when necessary, to move in winter, though the cost could be high. In 313 Maximinus ‘ ‘moved his army out of Syria when winter was at its most savage and with double marches rushed into Bithynia with an injured force; for the baggage animals of all sorts were lost to rain and snow, to mud, cold and exhaustion and their wretched carcasses in the road announced now to the soldiers the result ofthe future war and a similar slaughter’’ (Lact. DMP45.2-3).
As the emperor and his entourage moved, he kept on entering cities. There was a ceremonial process, known as adventus (‘‘arrival’’) that regulated the way in which the emperor interacted with his cities (MacCormack 1981). Outside the city gate, the town councilors assembled to honor the emperor, along with other important local figures, priests, and musicians. When Constantine arrived at Autun in 311, an orator claimed that ‘‘we decorated the roads by which he might come into the palace, with modest ornamentation, but with the standards of all our collegia, the statues of all our gods and a very small number of loud instruments which, in short bursts, we brought round to you often, by running’’ (Pan. 8 [5].8.4). Some cities were rarely visited (Autun’s only other known visit in this period was by Constantius I in 295), but others saw the emperor on many occasions, especially those on major communication routes like Trier, Milan, Serdica, Sirmium, Nicaea, Nicomedia, and Antioch. The late third century saw a series of new constructions in these cities to support emperors and their retinues. Typical features were a palace (for audiences), a hippodrome (for races and public appearances) - these two buildings were often linked - a treasury, and vast numbers of warehouses. In 310, a panegyrist described Trier: ‘‘I see a Circus Maximus, the rival I believe of that in Rome, I see basilicas and a forum, royal works, and a seat of justice are being raised to such a height that they promise to be worthy neighbours of the stars and the sky’’ (Pan. 7 [6].22.5). Troops and retinues were scattered throughout the city, often billeted on private individuals.
With emperors spending much of their time in new places or in or between frontier regions, the city of Rome continued to be marginalized. Diocletian went there only for his vicennalia in 303, but didn’t like the city. He was especially fond of Nicome-dia. Its attractions were similar to those of Byzantium, where Constantine founded his new city of Constantinople in 324. Both had good communications, lying on the main military route between the eastern and Danubian fronts, with good sea access. Constantine too was rarely in Rome - only three visits are recorded: in 312 to defeat Maxentius, in 315 for his decennalia and in 326 to celebrate his vicennalia (after celebrating it in 324 at Nicomedia). His tricennalia in 335, however, was celebrated in Constantinople. Although Constantinople went on to become a ‘‘second Rome,’’ it was not intended as such. It had no Senate initially, though its preferred status was shown by the establishment of a corn dole in 332 and the early existence of a praetor (Chron. Pasch. s. a. 332).
Constantinople also benefited from its imperial foundation by plundering other cities for suitable decoration. Churches were built there rapidly, but existing temples were left intact. It was impossible within Roman minds, pagan or Christian, to separate religion and the state. Peace on earth and even the harvest depended on treating the god or gods correctly. As Maximinus wrote in 312, ‘‘who can be so senseless or bereft of all intelligence as not to perceive that it is by the benevolent care of the gods that the earth does not refuse the seeds committed to it’’ (Euseb. Eccl. Hist. 9.7-8). Failure to do this had negative consequences. The emperor was the chief priest of Rome, the Pontifex Maximus, a post held by both Augusti under the tetrarchy (ILS 639). The Diocletianic persecutions of 303 began because sacrifices were turning out poorly on account of Christians being present. From 305, the civil wars following Diocletian’s retirement meant that imperial treatment of Christianity became politicized. Romans wanted to know whether the continuing problems were the result of allowing Christians freedom or because freedom had been denied to them. Galerius’ persecutions meant that support of Christianity could bring political benefits to his rivals. In the west, Constantine was tolerant from 306 and Maxentius did not persecute and even returned some property to Christians. In the east, Galerius cancelled his persecution in 311, in part due to a painful disease which he attributed to the Christian god. Maximinus, however, continued the persecution, and cities under his control, including Nicomedia and Antioch, banned Christians from meeting in their territory. This persecution was relaxed in winter 312, then cancelled in spring 313 immediately before his defeat (Mitchell 1988). Thus Licinius’ and Constantine’s toleration from June 313 (proclaimed in the Edict of Milan) was a late development. Its motivation too was typical, in that Licinius and Constantine explained that, having ‘‘discussed everything relevant to the public advantage and safety, we considered that, among those things which we saw would be relevant to many people, priority should be given to setting in order those matters involving reverence for the divinity, in order that we might give both to Christians and to everyone the freedom to follow whatever religion they wish, so that whatever divinity resides in the heavens might be well-disposed and favorable towards us and all who have been placed under our authority’’ (Lact. DMP 48.2). The same issue of concern for imperial unity can be seen in Constantine’s handling of the Arian controversy. Bishop Eusebius of Nicomedia, Licinius’ main residence, was at odds with bishop Alexander of Alexandria, and was supporting Arius against him. After the defeat of
Licinius in 324, Constantine became involved, in part because the issues were already discussed at Nicomedia. He dismissed the theological question (centering on the nature of the relationship of God the Father to God the Son) in favor of church unity, and wrote to both Arius and Alexander, asking whether they could agree to differ (Euseb. VC 2.64-72). When this proved impossible, he attempted to resolve the problem by summoning a council of bishops, i. e. a convocation of the entire church, representing both East and West. Constantine fixed the time, place, and agenda, attended and played an active part in the meeting at Nicaea in May 325. By the end of the council, only three of the delegates, Arius, Eusebius of Nicomedia, and Theognis of Nicaea, refused to sign anathemas against Arius and so were exiled. According to the emperor, ‘‘the decision of 300 bishops must be considered no other than the judgement of God’’ (Socr. Hist. Eccl. 1.9). Constantine then worked hard to persuade Arius to accept the council’s judgment. The Council of Jerusalem in 335, once reassured that Arius had been personally examined by Constantine and ascertained to be orthodox, re-admitted Arius to the church. Constantine’s concerns seem hardly theological. Edicts against heretics were issued in the same spirit of imperial unity rather than theological correctness (CTh. 16.5.2 [326]).
Emperors had a clear relationship with the divine powers. In the 270s and 280s, Aurelian and Carus had already described themselves as dominus et deus (‘‘lord and god’’) (Peachin 1990). This relationship continued in traditional fashion and was hardly affected by Christianity. Thus the emperor continued to hold the office of Pontifex Maximus and was given divine honors through the imperial cult, even if Christians did not always participate. An inscription from Arycanda in Lycia in 312, after quoting Maximinus’ statement on the care of the gods, asked Maximinus and Licinius that ‘‘injunctions be given for all to devote themselves steadfastly to the worship of the gods’’ (CIL 3.12132).The imperial cult continued to be celebrated by Christian emperors. In 333/5, Constantine allowed the construction of a temple dedicated to his family at Hispellum in Italy, provided that no sacrifices took place ( ILS 705), although other priests still erected inscriptions showing that they had performed all ‘‘public services’’ (leitourgeian), which presumably did include sacrifices (SEG 41.1390). And on the death of an emperor, he was often deified by the Senate, as happened to Diocletian, Constantius, and Constantine, for example. Imperial propaganda stressed the special status of emperors, making clear the divine sponsorship of their actions. An inscription from Dyrrachium mentioned ‘‘our lords Diocletian and Maximian, unconquered Augusti, born of gods and creators of gods’’ (ILS 629). This aspect was modified by Diocletian who devised new titles by which he associated himself with Jupiter and Maximian with Hercules. As with tetrarchic unity, this theme was disseminated widely. New legions were created, named Ioviani and Herculiani after these deities. When the theater of Pompey in Rome was restored by L. Aelius Helvius Dionysius, probably in 301-2, its new gates were named the porticus Iovia and porticus Herculia (ILS 621-2). Coins reinforced these associations, with lOVI CONSERVATORI on the reverse of many of Diocletian’s issues, HERCULI CONSERVATORI on Maximian’s reverses. This relationship with Jupiter and Hercules continued under the second tetrarchy (ILS 658-9, 681), with Licinius describing himself as IOVI CONSERVATORI into the 320s (RIC 7.67682). Non-Christian, though traditional, epithets, like SOL INVICTUS, were found on some of Constantine’s coins as late as 324.
Another tetrarchic change was the introduction of increasingly elaborate court ceremonial, by which court protocol was remodeled on Oriental principles. New officials, often eunuchs, are now attested as playing an important role in controlling access to the emperor. The praepositus sacri cubiculi (‘‘officer in charge of the sacred bedchamber’’) is first attested in 326, and the primiceriussacri cubiculi (there is little difference in these two titles) perhaps in 312, definitely in 326. Despised by contemporaries, their considerable power depended on the emperor’s favor (Hopkins 1978a). Once past the eunuchs, approaching an emperor involved a formal process of adoratio, kneeling and kissing the corner of the imperial robe, a practice apparently introduced by Diocletian (H. Stern 1954). The court was a difficult world, even if one could reach the emperor’s ear. Promotion was dependent on the emperor, who always played a role in appointing senior officials and could be swayed by personal factors. Constantine, for example, gave some preference to Christians. The most famous was Ablabius, who was vicarius of Asiana in 324/26, praetorian prefect in 329-37 and consul in 331. But Constantine also appointed Sopater, a pagan sophist from Syria, as an assessor at court because he was ‘‘captivated’’ by him. Sopater was later executed through a plot laid by Ablabius (Eun. VS 462). Politics affected cities as well as individuals. The Phrygian town of Orcistus, in appealing for an upgrade of its civic status to city, mentioned that all of its population were ‘‘followers of the most holy religion.’’ Since the petition was supported by Ablabius and favorably received by Constantine, they were probably Christians (MAMA 7.305).
Ruling the empire or even finding out what was happening required the emperor to exert his will. His voice could be heard directly and imperial visits were an effective way of reminding the empire of his existence. The imperial voice could be heard at a distance in many ways. Images of the emperor were everywhere, in government offices and on coins. All official documents contained references to his existence. Laws were posted which issued his commands (Matthews 1998). Judges enacted his law. Governors collected his taxes. And everywhere troops were present as a reminder of the consequences of disobeying the emperor’s will. The machinery functioned on a combination of fear and faith. Fear was guaranteed by the existence and use of a powerful army, intended to allow the emperor to defend himself and to protect the state. Without this support, imperial decisions could not be carried out - hence the harsh treatment of dissidents who denied the authority of the Roman emperor, especially in the army. The frequent military sacrifices on behalf of the emperor could be interpreted as idolatry by Christians, though many served as soldiers. When interrogating the reluctant conscript Maximilianus in 295, Cassius Dio, the proconsul of Africa, observed that ‘‘there are Christian soldiers in the sacred comita-tus of our lords Diocletian, Maximian, Constantius and Galerius and they serve’’ (acta Maximiliani 2.9). These included men like Aurelius Gaius, buried at Cotyaeum in Phrygia in the early fourth century. After serving throughout the empire, Aurelius left the army (perhaps because of the 303 persecutions) and ‘‘in tribute to Julia Arescusa my own wife most dear I have erected this stele from [the fruits of] my own labors as a memorial until the Resurrection’’ (Sartre 1983; SEG 31.1116). With the acceptance of Christianity, Christians had to serve as soldiers. The Biblical commandment that ‘‘thou shalt not kill’’ was no bar to service and at one of Constantine’s first church councils, at Arles in August 314, the assembled bishops agreed to excommunicate soldiers who put down their arms in peacetime; military service was clearly a necessity (Opt. App. 4, canon 3). However, even under Christian emperors, most troops remained pagan, drawn from the countryside where the majority were non-Christian until at least the end of the fourth century. Some veterans greeted the emperor in 320 (or 326): ‘‘when he had entered the headquarters (principia) and had been saluted by prefects and tribunes and by the viri eminentissimi, he was acclaimed, ‘Augustus Constantine, May the gods preserve you for us. Your safety is our safety’’’ (CTh. 7.20.2). The elite regiments of the Ioviani and Herculiani, created by Diocletian, still occupied the most privileged positions in the army at the end of the fourth century. But throughout the period, the army remained an instrument of the state, whether used by Galerius to destroy churches or to persecute Christians and Manicheans or by Constantine to destroy pagan temples and to enforce persecution of Donatists.
As with separating secular and religious, distinguishing civil from military is difficult. All arms of government service were described as militia, though this could be qualified as militia armata and militia officialis. The persecutions of Christians in Caesarea in Palaestina Prima were carried out by the governor’s office sending troops to investigate, using census lists created for taxation purposes. The overlap is exemplified by the office of praetorian prefect, usually held by two equestrians. Their backgrounds varied, though some were lawyers, like Hermogenianus under Diocletian (Corcoran 2000: 85-90). On occasion, prefects commanded the comitatus, as when Volusianus led an army of Maxentius against Alexander in Africa in 309, though most did not have extensive military backgrounds (Zos. 2.14.2). More usual were their other military duties, including recruiting and provision of supplies for the army, comitatus, and government officials, as well as feeding Rome (and from 332 Constantinople). Prefects also acted as judges. Constantine in 331 stated that ‘‘we do not permit appeals to be made from the praetorian prefects who alone should be described as judging in the divine stead (vice sacra) lest the veneration due to us should be seen as impugned’’ (CTh. 11.30.16). They also acted as the emperor’s chief of staff and were responsible for public works, roads, and the imperial post. After Constantine defeated Maxentius in 312 and Licinius in 324, the praetorian guards were disbanded and prefects ceased to have a military command role. Their numbers varied, since each emperor had his own prefect. Like emperors, they acted collegially (Feissel 1985 = SEG 35.1484; Feissel 1991).
Although one of the most powerful officials, praetorian prefects were only part of the machine of government. In the late third century, most other aspects of the rest of the empire were run from the comitatus by the several scrinia (departments), the principals of which were the magister libellorum (in charge of judicial petitions), the magister epistularum (imperial correspondence), and the magister memoriae (memoranda). This system had been completely reformed by the 330s. The office of prefect, perhaps over-powerful (in the third century, prefects had murdered and replaced emperors on more than occasion), and certainly demanding, with its financial, administrative, judicial, and military responsibilities, underwent restructuring. Late in Constantine’s reign, the military role of prefects was taken by new officers, the magister peditum and magister equitum (Zos. 2.33). The office of magister officiorum had appeared by 320 to oversee the various magistri scriniarum, as well as the agentes in rebus, imperial investigators. Constantine created the office of quaestor sacri palatii to draft imperial constitutions in place of the magister libellorum (Harries 1988). He also created a new rank between duces and prefects, that of comes, a companion of the emperor. In the third century, this was a description of a relationship to the emperor, but Constantine formalized this title as both an honor and a rank. As an honor it was attached to positions close to the emperor such as comes et magister militum. As a rank, it was usually given to senators, though subdivided into several grades (Mann 1977). Many of these officials met in the consistory, the advisory imperial council that included most of the senior officers of the comitatus, both civilian and military.
The way in which provinces were administered changed, too. Before Diocletian’s reign, the civil and military aspects of provinces were administered by the governor (usually a senatorial legatus, though there were already some equestrian governors: Pflaum 1976), the financial aspects by an equestrian procurator. By the end of Constantine’s reign, a province’s military aspects were administered by a dux, the civil and financial by the governor (praeses, corrector, consularis) (Mann 1977). The new military frontier commands often covered more than one civil province, producing officers such as the dux Pannoniae Primae et Norici Ripensis or the dux Aegypti Thebaidos utrarumque Libyarum ( AE 1934.7; ILS 701). These duces themselves were not new, though they became far more common than they had been in the third century. Duces could still carry out civic duties: e. g. in Scythica, Aurelius Firminianus built a city gate at Tomi under Diocletian and Maximian (286/93) (ILS4103), and late in his reign Constantine wrote to Ursinus, the dux of Mesopotamia, banning castration (CJust. 4.42.1). However, some governors may have retained military functions into Constantine’s reign, as suggested by a dedication from the tribune Successus to Arrius Maximus, consularis of Syria Coele (AE 1940 no. 168).
The separation of civil and military hierarchies had other consequences. Beginning in the early third century, many senatorial families ceased to compete for or hold government positions, and by the end of the century these families usually only held office as provincial governors (correctores) in Italy or as the proconsul of Asia, Achaea, or Africa. Even these commands were much smaller than they had been, Africa for example having been subdivided into three provinces. The urban prefecture of Rome was also a prestigious office, and one that did not require travel outside Italy. At the same time, other families, for the most part equites, concentrated on military positions. With no need to hold civic offices, often in Rome, Roman officers could now be career officers, rather than aristocrats with military responsibilities. There was thus the beginning of an imperial aristocracy based on holding offices rather than land. These changes also allowed the promotion of non-Romans into higher ranks, a process often described as ‘‘barbarization.’’ This was not a deliberate policy change, but an unintended consequence of the changes in command structures. Thus the Frank Bonitus fought for Constantine against Licinius and had a Roman wife, while Crocus, the Alamannic king present at Constantine’s accession in 306 was probably in command of troops (Amm. Marc. 15.5.33; Aur. Vict. Caes. 3). The promotion of many equestrians into the senatorial order also started to blur the distinctions between the two. Constantine did create a new senatorial rank of consularis for governors of some provinces, especially in Italy, but some of the holders had recent equestrian antecedents.
More emperors meant more soldiers, palaces, and administrators. In the words of Lactantius, ‘‘the provinces were divided into minute portions, and many praesides and a multitude of inferior officers lay heavy on each territory, and almost on each city.
There were also many rationales and magistri and vicarii of prefects’’ (DMP 7.4). The government of the late empire is often described as bigger than that of the early empire (Heather 1994; Garnsey and Humfress 2001: 36-8), although calculations of the small size of the early imperial administration perhaps underestimate the role played by governor’s households in running the state. The number of provinces was increased in Diocletian’s reign, as they were, in Lactantius’ phrase, ‘‘chopped into slices’’ (DMP 7.4); an early-fourth-century document, the Verona List, lists almost 100 provinces (T. D. Barnes 1982: 195-225). The increase in numbers took place gradually and there was no single edict changing the structure of all the empire’s provinces in one fell swoop. Nor was this a new practice. In Anatolia, Isauria had been carved out of Cilicia by the reign of Gordian III, if not earlier (CIL 3.6783), and Caria and Phrygia was split off as a province from Asia in the 250s, before being split again into separate provinces in 301/5 (Roueche 1989). Under the tetrarchy, many provinces were split into smaller parts: Asiana, for example, went from being one province to seven. At the same time, eight provinces were carved out of Italy. Many small provinces, however, continued unchanged. The process of splitting provinces continued after Diocletian. Licinius created Aegyptus Iovia, Aegyptus Herculia, and Arabia Nova out of Aegyptus in 314/15, although he reassembled them by 324.
The increase in the number of provinces and officials led to the development by Diocletian of a new level of administration above provincial governors, that of vicarius, technically deputies of the praetorian prefects (vicarii agens vices praefec-torum praetorio) (Barnes 1982: 141-7). There were 12 vicarii, equally divided between east and west, who were responsible for dioceses, groups of between six and 18 provinces. Most of their duties were judicial and financial. The diocesan structure was used to organize mints and by the end of Diocletian’s reign a mint had been established in most dioceses, usually at cities frequented by emperors, such as Nicomedia or Trier. This was a gradual process; Spain never had a mint, perhaps because of its lack of garrison, and one was not established in Viennensis until 313. It was not a rule, however: the only mint in north Africa, at Carthage, was moved to Ostia c.307. When Domitius Alexander revolted in Africa a few years later, his coinage was of noticeably poor quality (Hendy 1972, 1985).
Reducing the load on provincial officials made the empire more efficient, since governors were now responsible for a much smaller number of cities. Their main responsibilities were to collect taxes, hear legal cases, and enforce the imperial will. The governor’s role in tax collection changed as a result of Diocletian’s reforms of the taxation system. Managing imperial income was complicated. The income from the substantial imperial estates (in cash or kind), many of which were rented out, was handled by the res privata. Cash payments from the rest of the empire were handled by the res summa, which became the sacrae largitiones from Constantine’s reign. The res summa collected taxes levied in cash, as well as the aurum coronarium (and the chrysargyron, first attested in 325), and paid out donatives. Its role became more important with the increasing emphasis on cash income in the fourth century. A third stream of income came from goods levied in kind by the praetorian prefect to support the army and comitatus. In 297, Diocletian regularized this process as the annona militaris. Rates were not fixed, but based on state needs. The levy was based on land units (iugera) and head counts (capita), assessed for every farm, village, and city (many of which had previously been exempt) following extensive local surveys (Millar 1993a: 535-44). Although the way in which these were calculated varied regionally, this did not affect the calculations of the prefect. When the system was introduced, censuses were made, but these were rarely adjusted. It was possible, though, to adjust taxation rates. They usually went up, though in the late 350s, the Caesar Julian was famously able to lower assessments in Gaul from 25 solidi per caput to seven (Amm. Marc. 16.5.14). The goods were collected by tax collectors, who were personally responsible for taxes; any shortfall then fell on the local council which appointed them. Tax collection could be popular with collectors, as it gave an opportunity to make money if more was collected than required. Italy had always been subject to collections for the annona, so with the main state demands now coming in this form, it now paid more. However, when Severus attempted to impose the capitatio on urban populations Italy in 306 it was unpopular, enabling Maxentius’ seizure of power (Lact. DMP 26.2). Assessing the burden of the taxation system is difficult, though Diocletian’s work probably increased the efficiency of collection, especially of the annona. Lactantius said that the beneficiaries of taxation exceeded the tax-payers, though Aurelius Victor thought that taxes were much more tolerable at this period than they were two generations later (Lact. DMP 7.3; Aur. Vict. Caes. 39.32).
With much of the taxation collected in kind, the state was able to insulate itself from some of the inflationary problems of the period. Coins were minted in gold, silver, and bronze. The traditional silver coinage, the denarius, suffered particularly from debasement, though this did not affect gold coinage, since the exchange rate was based on metal content, not face value. The relationship between the bronze and silver coinages fluctuated continually. Although bronze was minted for military pay and for small change, it was not withdrawn through tax collection. Continued minting thus increased the money supply and fueled inflation. Coinage reforms had already been attempted by Aurelian. Diocletian in 286 struck gold at 60 to the pound and created a new silver coin, the argenteus, struck at 96 to the pound from pure silver in 294. Another response to the crisis was the Price Edict of 301, which was intended primarily to regulate government purchases and to protect soldiers’ income. This set a maximum price for a modius of wheat at 100 denarii, but by 335 a modius cost c.6,000 denarii (P. Lond. 1914), i. e. 60 times as much (Corcoran 2000: 205-33). Changing the coins in circulation and fixing prices was not enough. It was not until Constantine’s creation of gold solidi (struck at 72 to the pound) from 309 that some long-term stability was brought to the currency. This coinage could only be spread as Constantine conquered territory, so it was not until 324 that gold solidi were a universal currency. Constantine benefited from his capture of the treasuries of his civil war rivals and from his confiscation of temple treasures (emulating Maximinus in the 230s: Herod. 7.3.5), both of which allowed large amounts of the new coinage to be introduced at once. A renewed emphasis on taxes in precious metals (and commutation) and the introduction of new taxes (the chrysargyron) allowed the government to keep the coinage stable (Hendy 1985: 284-5).
Governors also heard legal cases, ideally in public (CTh. 1.16.6 [331]). Although many governors had some legal experience, this was not a requirement for appointment. Resolving cases was made somewhat easier for judges by two collections of law in Diocletian’s reign, the Codex Gregorianus (first edition c.292) and the Codex Hermogenianus (first edition 295). These collections were composed mostly of rescripts (imperial replies to private petitions), while most of the Constantinian laws preserved (generally in the Codex Theodosianus) are edicts (imperial pronouncements). These different focuses reflect different collection strategies, rather than any change in imperial practice (Corcoran 2000). Governors did not always use such aids, however, but often returned appeals to lower officials. In 318, Valerius Ziper, praeses of Aegyptus Herculia, replied to a petition from Aurelius Isidorus concerning his dispute with a fellow-villager over a debt, ‘‘the praepositus pagi [a local official], after having decided between you, will provide the appropriate assistance in the matter of the debt owed you’’ (P. Cair. Isid. 76). The private petitions preserved show that individuals of low status, including women and slaves, could transmit petitions to the emperor and receive a response. Some even managed this twice, like Calpurnia Aristaeneta at Maximian’s court in Milan in 286 (FV 282). Governors did not have a monopoly on jurisdiction; military courts existed as well and Constantine empowered bishops to hear civil suits in certain circumstances (Harries 1999: 191-203). By 333 he ruled that any party in a legal case before the verdict was passed could appeal to a bishop’s jurisdiction, the bishop’s judgment was not subject to appeal, and had to be executed by the state. When his Christian praetorian prefect Ablabius questioned this, it was explicitly reaffirmed by Constantine (Sirm. 1 [333]).
Governors were also responsible for many enactments of the imperial will, either in response to an edict or as a result of a direct order delivered by letter. Some were simple, as when Diocletian wrote to Aurelius Isidorus, the procurator of the Thebaid, in 299, giving him instructions about the transportation of columns of granite from Syene to Alexandria (P. Panop. Beatty 2.50). Others were more complicated. A dispute between two Christian factions (orthodox and Donatist) in Carthage led to Constantine’s intervention in several ways, including by means of letters to the governor. Once Constantine had defeated Maxentius in 312, he wrote two letters to Anullinus, proconsul of Africa, which showed clear and pointed support for the Catholics. Although this was a religious dispute, Constantine was using both secular and ecclesiastical channels. The Donatists proceeded to appeal to Constantine three times over the next three years. Constantine responded by calling councils at Rome in 313 and Arles in 314, summoning ecclesiastical officials in his capacity as secular ruler. Constantine, who was present, called the judgment of Arles on the Donatists in 314 a ‘‘Judgment of Christ: for I say - and it is the truth - that the judgment of priests ought to be regarded as if the Lord himself sat in judgment’’ (Opt. App. 5). A final resolution of the dispute was delayed in 316 because of the war against Licinius, but in spring 317 Constantine began exiling the Donatist leaders and confiscating their property. However, imperial persecution of Christians and creation of martyrs was a hard concept to defend or implement and persecution tailed off rapidly. By 321, the Donatist exiles had been recalled, and Constantine wrote to the Catholic bishops, saying that revenge would be left to God. For Constantine, this appears to have been as much about imperial unity as it was about religion; there were no theological issues involved. It was difficult for imperial officials to enforce imperial commands while living in a community among their peers and many must have been grateful that their terms of office were short.
The half-century between Diocletian’s accession and Constantine’s death was a period of significant change and development in the Roman state. It is important to remember that change occurred both before and after this period. Most measures were not new, but were institutionalizations of existing practices. Too much emphasis can easily be placed on Diocletian and Constantine personally and not enough on their imperial colleagues. The most significant change was in the restructuring of administrative hierarchies, with the state now run by imperial officials rather than by equestrian and senatorial aristocrats. There was more government in the fourth century than there had been earlier, though it remains unclear how heavy the demands were or whether the state actually strangled efficiency. Thus the demands of supporting multiple emperors and their courts as well as new provincial governors, vicarii and duces, need to be set against more efficient collection of taxation and judicial process. There was also a secession of part of the world from imperial control with the creation of a Christian church, though the problem of who was its master - emperor or God - was still unresolved when Constantine died. Lastly, though the framework of the empire itself may have been more efficient, government itself, as always, depended on the people involved - exemptions and contradictions in policy and enforcement were frequent.