THIRD CENTURY.] ROME 777 Aurelian in 273 ; in the next year the Gallic empire came to an end by the surrender of Tetricus, and the successors of Aurelian Tacitus, Probus, and Carus (275-282) were at least rulers over the whole extent of the empire. baric While rival generals were contending for the imperial '* purple, the very existence of the empire which they 1S> aspired to rule was imperilled by foreign invasion. As early as 236 a new enemy, the Alemanni, had crossed the Rhine, but had been driven back by the valour of Maxi- minus (238), and in the same year the Goths first appeared on the banks of the Danube. It was, however, during the period of internal dissension and civil war from the reign of Philip (244-249) to the accession of Claudius (268) that the barbarians saw and used their opportunity. From across the Rhine bands of Alemanni and Franks swept over Gaul and Spain, and even descended upon the coasts of Africa, until their raids were checked by the Gallic emperor Postumus (253-259). Far more tlL -- destructive were the raids of the Goths. 1 Towards the close of the reign of Philip (247) they crossed the Danube, and overran Mcesia, Thrace, and Macedonia. In 251 they defeated and slew the emperor Decius ; and, though his successor Gallus purchased a temporary peace by lavish gifts, the province of Dacia was finally lost to Rome. The Gothic raids by sea which began under Valerian (253-260) were even more destructive. Their fleets issuing from the ports of tho Black Sea ravaged the seaboard of Asia Minor, and returned laden with the spoils of the maritime towns. In the reign of Gallienus (260-268) a fleet of five hundred sail appeared off the coasts of Greece itself; Athens, Corinth, Argos, and Sparta were sacked, and Epirus laid waste. On the death of Gallienus (268) the Goths once more marched south- ward, but in the new emperor Claudius they were con- fronted at last by an able and resolute opponent. They were decisively defeated and driven back across the Danube (269). Claudius died of the plague in the next year, but by his successor Aurelian Roman authority was established in Mcesia and Pannonia, and the Danube frontier was put once more in a state of efficient defence. Five years later (276) Probus repulsed a raid of the Franks and Alemanni, and restored peace on the Rhine. But the rule of Rome now stopped short, as in the reign of Tiberius, at the line of the two great rivers ; all that had been acquired beyond since the time of Vespasian was abandoned, and on the further banks of the Rhine and Danube stood, in the place of friendly or subject tribes, a threatening array of hostile peoples. At the close of the 2d century the growing weakness of Parthia seemed to promise an immunity from danger on the Eastern frontier. But with the revolution which placed the Sassanidse upon the throne the whole situation was changed. 2 The new dynasty was in blood and religion Persian ; it claimed descent from Cyrus and Darius, and aspired to recover from Western hands the dominions which had once been theirs. In 230 Artaxares (Ardashir) had formally demanded from Severus Alexander the restitu- tion of the provinces of Asia, had invaded Mesopotamia, now a Roman province, and even advanced into Syria. Twenty years later his successor Sapor again crossed the Euphrates ; in 260, ten years after Decius's defeat by the Goths, the emperor Valerian was conquered and taken prisoner by the Persians, who poured triumphantly into Syria and captured Antioch. But here for the time their successes ended. Three years later Odaenathus of Pal- myra drove them back, and held the East securely in the name of Rome. On the fall of Zenobia (273) they gained possession for a time of Armenia and Mesopotamia, but 1 Gibbon, i. chap. x. ; Mommsen, v. 216. 2 Gibbon, i. chap. viii. ; Mommsen, v. 411 ; cf. PERSIA. were driven out by the emperor Carus (282), and the frontier line as fixed by Septimius Severus was restored. Although any serious loss of territory had been avoided, State o the storms of the 3d century had told with fatal effect theem upon the general condition of tho empire. The " Roman ^^ Q peace " had vanished ; not only the frontier territories, O f the but the central districts of Greece, Asia Minor, and even 3d ecu- Italy itself, had suffered from the ravages of war, and turv - the fortification of Rome by Aurelian was a significant testimony to the altered condition of affairs. War, plague, and famine had thinned the population and crippled the resources of the provinces. On all sides land was running waste, cities and towns were decaying, and commerce was paralysed. Only with the greatest difficulty were suf- ficient funds squeezed from the exhausted tax-payers to meet the increasing cost of the defence of the frontiers. The old established culture and civilization of the Medi- terranean world rapidly declined, and the mixture of barbaric rudeness with Oriental pomp and luxury which marked the court, even of the better emperors, such as Aurelian, was typical of the general deterioration, which was accelerated by the growing practice of settling bar- barians on lands within the empire, and of admitting them freely to service in the Roman army. PERIOD II.: 284-476 A.D. (a) From the Accession o/There- Diocletian to the Death of Tkeodosius (284-395 A.D.). fo r ms ( The work begun by Aurelian and Probus, that of fortify- ti ^ c a 6 ing the empire alike against internal sedition and foreign Consta invasion, was completed by Diocletian and Constantine tiue. 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. In the Augusi second year of his reign Diocletian associated Maximian J5f d with himself as colleague, and six years later (292) the hands of the two "Augusti" were further strengthened 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 ; 4 and the considerations in favour of it at the time were strong. It divided the overwhelming burdens and respon- sibilities of government, without sacrificing the unity cf the empire ; for, although to each of the Augusti and Ceesars 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 Caesars 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 dis- tribution 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 (Jonstantius, Galerius, and Diocletian, the central districts of Italy and Africa to Maximian. 5 A 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, Italy and her Invaders, i. 202 sq. ; Preuss, Diocletian, Leipsic, 1869.
- Mommsen, Staatsrecht, ii. 1065 sq. Verus was associated with
Marcus Aurelius as Aiigustus ; 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. XX. 98
