1902 Encyclopedia > Rome > Ancient Roman History - From the Accession of Diocletian to the Death of Theodosius (284-395 A.D.)

(Part 11)



Period II: 284-476 A.D.
(a) From the Accession of Diocletian to the Death of Theodosius (284-395 A.D.)

The Reforms of Diocletian and Constantine

The work begun by Aurelian and Probus, that of fortifying the empire alike against internal sedition and foreign invasion, was completed by Diocletian and Constantine the Great, whose system of government, novel as it appears at first sight, was in reality the natural and inevitable outcome of the history of the previous century.3 Its object was twofold, to give increased stability to the imperial authority itself, and to organize an efficient administrative machinery throughout the empire.

Augusti and Caesares

In the second year of his reign Diocletian associated Maximian with himself as colleague, and six years later (292) the hands of the two "Augusti" were further rtrengthened by the proclamation of Constantius and Galerius as " Caesares." Precedents for such an arrangement might have been quoted from the earlier history of the empire ; and the considerations in favour of it at the time were strong. It divided the overwhelming burdens and responsibilities of government, without sacrificing the unity of the empire; for, although to each of the Augusti and Caesars a separate sphere was assigned, the Caesars were subordinate to the higher authority of the Augusti, and over all his three colleagues Diocletian claimed to exercise a paramount control. It at least reduced the too familiar risk of a disputed succession by establishing in the two Ccsars the natural successors to the higher position of Augusti, and finally it satisfied the jealous pride of the rival armies of the empire by giving them what they had so constantly claimed, imperatores of their own. The distribution of power between Diocletian and his colleagues followed those lines of division which the feuds of the previous century had only too clearly marked out. The armies of the Rhine, the Danube, and of Syria fell to the lot respectively of Constantius, Galerius, and Diocletian, the central districts of Italy and Africa to Maximian.5

Altered Character of the Imperial Authority

A second point in the new system was the complete and final emancipation of the imperial authority from all constitutional limitation and control. The last lingering traces of its republican origin disappear. The emperors from Diocletian onwards are autocrats in theory as well as in practice. The divided powers, the parallel jurisdictions, the defined prerogatives of the Augustan system have all vanished. There is but one legal authority throughout the empire, that of the emperor himself ; and that authority is absolute. This avowed despotism Diocletian, following in the steps of Aurelian, hedged round with all the pomp and majesty of Oriental monarchy. The final adoption of the title "dominus," so often rejected by earlier emperors, the diadem on the head, the robes of silk and gold, the replacement of the republican salutation of a fellow citizen by the adoring prostration even of the highest in rank before their lord and master, were all significant marks of the new regime.

Levelling Policy of Diocletian

In the hands of this absolute ruler was placed the entire control of an elaborate administrative machinery. Most of the old local and national distinctions, privileges, and liberties which had once flourished within the empire had already disappeared under the levelling influence of imperial rule, and the levelling process was now completed. Roman citizenship had, since the edict of Caracalla, ceased to be the privilege of a minority.

Degradation of Italy and Rome

Diocletian finally reduced Italy and Rome to the level of the provinces : the provincial land-tax and provincial government were introduced into Italy, while Rome ceased to be even in name the seat of imperial authority.

The New Administrative System

Throughout the whole area of the empire a uniform system of administration was established, the control of which was centred in the imperial palace, and in the confidential ministers who stood nearest the emperor's person. Between the civil and military departments the separation was complete. At the head of the former, at least under the completed organization of Constantine, were the four prefects, next below them the " vicarii," who had charge of the " dioceses," below these again the governors of the separate provinces ("praesides," "correctores," "consulares"), under each of whom was a host of minor officials. Parallel with this civil hierarchy of prefects, vicars, praesides, and smaller " officiates " was the series of military officers, from the "magistri militum," the "duces," and "comités" downwards. But the leading features of both are the same. In both there is the utmost possible subordination and division of authority. The subdivision of provinces, begun by the emperors of the 2d century, was systematically carried out by Diocletian, and either by Diocletian or by Constantine the legion was reduced to one-fifth of its former strength. Each official, civil or military, was placed directly under the orders of a superior, and thus a continuous chain of authority connected the emperor with the meanest official in his service. Finally, the various grades in these two imperial services were carefully marked by the appropriation to each of distinctive titles, the highest being that of "illustris," which was confined to the prefects and to the military magistri and comites, and to the chief ministers.

Effects of these Reforms

There can be little doubt that on the whole these reforms prolonged the existence of the empire, by creating a machinery which enabled the stronger emperors to utilize effectively all its available resources, and which even to some extent made good the deficiencies of weaker rulers. But in many points they failed to attain their object. Diocletian's division of the imperial authority among colleagues, subject to the general control of the senior Augustus, was effectually discredited by the twenty years of almost constant conflict which followed his own abdication (305-323). Constantine's partition of the empire among his three sons was not more successful in ensuring tranquillity, and in the final division of the East and West between Valens and Valentinian (364) the essential principle of Diocletian's scheme, the maintenance of a single central authority, was abandoned. The "tyrants," the curse of the 3d century, were far from unknown in the 4th, and their comparative paucity was due rather to the hold which the house of Constantine obtained upon the allegiance of their subjects than to the system of Diocletian. This system, moreover, while it failed altogether to remove some of the existing evils, aggravated others. The already overburdened financial resources of the empire were strained still further by the increased expenditure necessitated by the substitution of four imperial courts for one, and by the multiplication in every direction of paid officials. The gigantic bureaucracy of the 4th century proved, in spite of its undoubted services, an intolerable weight upon the energies of the empire.

Constantine the Great

Diocletian and Maximian formally abdicated their high office in 305. Eighteen years later Constantine, the sole survivor of six rival emperors, united the whole empire under his own rule.

Recognition of Christianity

His reign of fourteen years was marked by two events of first-rate importance,—the recognition of Christianity as the religion of the empire, and the building of the new capital at Byzantium. The alliance which Constantine inaugurated between the Christian church and the imperial government, while it enlisted on the side of the state one of the most powerful of the new forces with which it had to reckon, imposed a check, which was in time to become a powerful one, on the imperial authority.


The establishment of the new "City of Constantine" as a second Rome, with a second senate, a prefect of the city, regiones, and even largesses, did more than proclaim once again the deposition of Rome from her old imperial position. It paved the way for the final separation of East and West by providing the former for the first time with a suitable seat of government on the Bosphorus. The death of Constantine in 337 was followed, as the abdication of Diocletian had been, by the outbreak of quarrels among rival Caesars. Of the three sons of Constantine who in 337 divided the empire between them, Constantine the eldest fell in civil war against his brother Constans ; Constans himself was, ten years afterwards, defeated and slain by Magnentius; and the latter in his turn was in 353 vanquished by Constantine's only surviving son Constantius.

Constantius II (351-363 A.D.)

Thus for the second time the whole empire was united under the rule of a member of the house of Constantine. But in 355 Constantius reluctantly granted the title of Caesar to his cousin Julian and placed him in charge of Gaul, where the momentary elevation of a tyrant, Silvanus, and still more the inroads of Franks and Alemanni, had excited alarm. But Julian's successes during the next five years were such as to arouse the jealous fears of Constantius. In order to weaken his suspected rival the legions under Julian in Gaul were suddenly ordered to march eastward against the Persians (360).

Julian (361-363 A.D.)

They refused, and when the order was repeated replied by proclaiming Julian himself emperor and Augustus. Julian, with probably sincere reluctance, accepted the position, but the death of Constantius in 361 saved the empire from the threatened civil war. The chief importance of the career of Julian, both as Caesar in Gaul from 355 to 361 and during his brief tenure of sole power (361-363), lies, so far as the general history of the empire is concerned, in his able defence of the Rhine frontier and in his Persian campaign ; for his attempted restoration of pagan and in especial of Hellenic worships had no more permanent effect than the war which he courageously waged against the multitudinous abuses which had grown up in the luxurious court of Constantius. But his vigorous administration in Gaul undoubtedly checked the barbarian advance across the Rhine, and postponed the loss of the Western provinces, while, on the contrary, his campaign in Persia, brilliantly successful at first, resulted in his own death, and in the immediate surrender by his successor Jovian of the territories beyond the Tigris won by Diocletian seventy years before.

Jovian (363-364 A.D.). Valentian I (364-375 A.D.). Division of the Empire.

Julian died on June 26, 363, his successor Jovian on February 17, 364; and on the 26th of February Valentinian was acknowledged as emperor by the army at Nicaea. In obedience to the expressed wish of the soldiers that he should associate a colleague with himself, he conferred the title of Augustus upon his brother Valens, and the long-impending division of the empire was at last effected,—Valentinian became emperor of the West, Valens of the East. From 364 till his death in 375 the vigour and ability of Valentinian kept his own frontier of the Rhine tolerably intact, and prevented any serious disasters on the Danube.

Valens (364-378 A.D.). Revolt of the Goths.

But his death, which deprived the weaker Valens of a trusted counsellor and ally, was followed by a crisis on the Danube, more serious than any which had occurred there since the defeat of Decius. In 376 the Goths, hard pressed by their new foes from the eastward, the Huns, sought and obtained the protection of the Roman empire. They were transported across the Danube and settled in Moesia, but, indignant at the treatment they received, they rose in arms against their protectors. In 378 at Hadrianople Valens was defeated and killed; the victorious Goths spread with fire and sword over Illyricum, and advanced eastward to the very walls of Constantinople.

Theodosius I. (378-395 A.D.)

Once more, however, the danger passed away. The skill and tact of Theodosius, who had been proclaimed emperor of the East by Gratian, conciliated the Goths ; they were granted an allowance, and in large numbers entered the service of the Roman emperor. The remaining years of Theodosius's reign (382-395) were mainly engrossed by the duty which now devolved upon the emperor of the East of upholding the increasingly feeble authority of his colleague in the West against the attacks of pretenders. Maximus, the murderer of Gratian (383), was at first recognized by Theodosius as Caesar, and left in undisturbed command of Gaul, Spain, and Britain; but, when in 386 he proceeded to oust Valentinian II. from Italy and Africa, Theodosius marched westward, crushed him, and installed Valentinian as emperor of the West. In the very next year, however, the murder of Valentinian (392) by Arbogast, a Frank, was followed by the appearance of a fresh tyrant in the person of Eugenius, a domestic officer and nominee of Arbogast himself.

Division of the Empire between Arcadius and Honorius

Once more Theodosius marched westward, and near Aquileia decisively defeated his opponents. But his victory was quickly followed by his own illness and death (395), and the fortunes of East and West passed and into the care of his two sons Arcadius and Honorius.


3 See Gibbon, vol. iii., chap. xvii.; Marquardt, Staatsverw., i. pp. 81, 336, 337, ii. 217 sq.; Madvig, Verf. d. Rom''Reichs, i. 585 ; Booking, Notitia Dignitatum, Bonn, 1853 ; Hodgkin, Haly and her Invaders, i. 202 sq.; Preuss, Diocletian, Leipsic, 1869.
4 Mommsen, Staatsrecht, ii. 1065 sq. Verus was associated with Marcus Aurelius as Augustus ; Severus gave the title to his two sons. The bestowal of the title "Caesar" on the destined successor dates from Hadrian. Mommsen, op. cit., 1044.
5 The division was as follows :—(1) Diocletian—Thrace, Egypt, Syria, Asia Minor ; (2) Maximian—Italy and Africa ; (3) Galerius—_ Illyricum and the Danube; (4) Constantius—Britain, Gaul, Spain. See Gibbon, ii. 68 ; Aurelius Victor, c. 39.

Aurel. Victor, 39; Eutrop., ix. 26.
Marquardt, Staatsverw., i. 80-83, wdiere a list is given of the seventeen so-called " provinciae " into which Italy, together with Sicily, Sardinia, and Corsica, was divided. Each had its own governor ; the governors were subject to the two vicarii (vie. urbis, vie. Italite), and they in turn to the prefect of Italy, whose prefecture, however, included as well Africa and Western Illyricum.
The seats of government for Diocletian and his three colleagues were Milan, Treves, Sirmium, Nicomedia.
For these last, see Gibbon, ii. chap. xvii. p. 325 ; cf. also Notitia Dignitatem and Booking's notes.
'' Praefecti praetorio." The four prefectures were Oriens, Illy-ricum, Italia, Gallia, to which must be added the prefectures of Rome and Constantinople.
There were 12 dioceses and 116 provinces ; cf. in addition to the authorities mentioned above, Bethmann-Hollweg, Civil-Prozess, iii.; Walter, Gesch. d. Mom. Rechts, i. pp. 428 sq. (Bonn, 1845).
For thii and other changes in th:¡ military organization, see

8 The grades were as follows : illustres, spectabiles, clarissimi, per-fectissimi, egregii. For the other insignia, see Madvig, ii. 590, and the Notitia Dignitatum.

In especial against the overweening influence of the eunuchs, an
influence at once greater and more pernicious than even that of the imperial freedmen in the days of Claudius.

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