Constantius was primarily interested in religious affairs. His interventions created a “caesaro-papism” that was unfavourable to the church, for after the Battle of Mursa the emperor had become violently Arian. The Christological problem had moved to the forefront. In 360 Constantius obtained a new creed by force from the Council of Constantinople, which, rejecting the notion of “substance” as too risky, declared only that the Son was like the Father and thus left the problem unresolved. Pagans as well as orthodox Nicaeans (Homoousians) and extremist Arians (Anomoeans) were persecuted, for in 356–357 several edicts proscribed magic, divination, and sacrifices and ordered that the temples be closed. But when Constantius visited Rome in 357, he was so struck by its pagan grandeur that he apparently suspended the application of these measures. The reign of Julian
Julian, who had been spared because of his tender age from the family butchering in 337, had been brought up far from the court and was undoubtedly intended for the priesthood. Nevertheless, he had been allowed to take courses in rhetoric and philosophy at Ephesus and later at Athens; he developed a fondness for Hellenic literature, and he secretly apostatized around 351. When he became sole emperor at the end of 361, he proclaimed his pagan faith, ordered the restitution of the temples seized under Constantius, and freed all the bishops who had been banished by the Arians, so as to weaken Christianity through the resumption of doctrinal disputes. The religion he himself espoused was compounded of traditional non-Christian elements of piety and theology, such as might have been found in any fairly intellectual person in the preceding centuries, along with elements of Neoplatonism developed by Porphyry and Iamblichus of two or three generations earlier, and, finally, much of the organization and social ethic of the church. From Neoplatonism he learned the techniques of direct communication with the gods (theurgy) through prayer and invocation; from the church he adopted, as the church itself had adopted from the empire’s civil organization, a hierarchy of powers: provincial, metropolitan, urban, with himself as supreme pontiff. His deep love of traditional higher culture, moreover, provoked his war on Christian intellectuals and teachers who, he protested, had no right to Homer or Plato. Many Christians both before and later concurred with him, being themselves troubled by the relation between Christianity and inherited literature and thought, steeped as both were in pagan beliefs.
In the latter part of his 18-month reign, Julian forbade Christians from teaching, began the rebuilding of the Temple at Jerusalem, restored many pagan shrines, and displayed an exaggerated piety. Whereas Constantine (and his sons to a lesser degree) had introduced a huge number of coreligionists into the upper ranks of the army and government, achieving a rough parity between the members of the two religions, Julian began to reverse the process. Within a short while Julian was successful enough in his undertaking to have aroused the fear and hatred of the Christians, who for a long time thought of him as the Antichrist.
In the political realm, Julian wished to return to the liberal principate of the Antonines—to a time before the reforms of Diocletian and Constantine, whom he detested. He put an end to the terrorism of Constantius’ eunuchs and agentes in rebus and reduced the personnel and expenditures of the court, while he himself lived like an ascetic. In the provinces he lightened the financial burden on individuals by reducing the capitatio, and on cities, by reducing the aurum coronarium and restoring the municipal properties confiscated by Constantius. On the other hand, he increased the number of curiales by reinstating numerous clerks in an attempt to return the ancient lustre to municipal life. Thus, he earned the gratitude of pagan intellectuals, who were enamoured of the past of free Greece; and Ammianus made him the central hero of his history.
Taking up Trajan’s dream, Julian wished to defeat Persia definitively by engaging the empire’s forces in an offensive war that would facilitate a national reconciliation around the gods of paganism. But his army was weak—corrupted perhaps by large numbers of hostile Christians. After a brilliant beginning, he was defeated near Ctesiphon and had to retrace his steps painfully; he was killed in an obscure encounter on June 26, 363.
Julian’s successor, Jovian, chosen by the army’s general staff, was a Christian, but not a fanatic. He negotiated a peace with Shāpūr, by which Rome lost a good part of Galerian’s conquests of 298 (including Nisibis, which had not surrendered) and abandoned Armenia. He also restored tolerance in religious affairs, for he neither espoused any of the heresies nor persecuted pagans. In February 364 he died accidentally. The reign of Valentinian and Valens
Once again the general staff unanimously chose a Pannonian officer—Valentinian, an energetic patriot and, like Jovian, a moderate Christian—but he had to yield to the rivalry of the armies by dividing authority. Taking the West for himself, Valentinian entrusted the East to his brother Valens, an inexperienced man whom he raised to the rank of Augustus. For the first time the two parts of the empire were truly separate, except for the selection of consuls, in which Valentinian had precedence.
Although he served the state with dedication, Valentinian could be brutal, choleric, and authoritarian. His foreign policy was excellent: all the while he was fighting barbarians (the Alemanni in Gaul, the Sarmatians and Quadi in Pannonia) and putting down revolts in Britain and Africa (notably that of the Berber Firmus) with the aid of his top general, Theodosius the Elder, he was taking care to improve the army’s equipment and to protect Gaul by creating a brilliant fortification. His domestic measures favoured the curiales and the lower classes: from then on, taxes would be collected exclusively by officials; the protection of the poor was entrusted to “defenders of the plebs,” chosen from among retired high officials (honorati). Nevertheless, needs of state obliged him to accentuate social immobility, to reinforce corporation discipline and official hierarchization, and to demand taxes ruthlessly. At first he was benevolent to the Senate of Rome, supervised the provisioning of the city, and legislated in favour of its university, the nursery of officials (law of 370). But beginning in 369, under the influence of Maximin, the prefect of Gaul, he initiated a period of terror, which struck the great senatorial families. Meanwhile, religious peace reigned in the West, tolerance was proclaimed, and after some difficulty, Rome found a great pope in Damasus, who, beginning in 373, actively supported the new bishop of Milan, St. Ambrose, an ardent defender of orthodoxy.
In the East, Valens, who was incapable and suspicious, had fallen under the influence of legists, such as the praetorian prefect Modestus. The beginning of Valens’ reign was shadowed by the attempted usurpation of Procopius (365–366), a pagan relative of Julian’s who failed and was killed by the army, which remained faithful to Valens. Modestus instituted harsh persecutions in Antioch of the educated pagan elite. Valens was a fanatic Arian, who exiled even moderate Nicaean bishops and granted to Arians favours that aroused violent reactions from the orthodox, whose power had increased in the East. Valens’ policies made the East prey to violent religious passions.
On the Danube, Valens fought the Visigoths and made a treaty with their king, Athanaric, in 369; but in 375 the Ostrogoths and the Greutingi appeared on the frontiers, pushed from their home in southern Russia by the powerful Huns. In 376 Valens authorized the starving masses to enter Thrace; but, being exploited and mistreated by the officials, they soon turned to uncontrollable pillaging. Their numbers continually increased by the addition of new bands, until finally they threatened Constantinople itself. Valens sent for aid from the West, but without waiting for it to arrive he joined battle and was killed in the Adrianople disaster of 378, which to some critics foreshadowed the approaching fall of the Roman Empire.