THEODOSIUS I., emperor of Rome, surnamed the Great, was the son of Theodosius, Valentinian's great general, who in 368-69 drove back the Picts and Scots from the Roman territories in Britain, and, after other successes on the Continent, was at last despatched to sup-press the revolt of Firmus in Mauretania (372). Shortly after (376), the elder Theodosius, despite his great services, was put to death by order of Valens, probably through fear lest he should be the Theodosius or Theodore whom the prophetic tripod indicated as the future emperor.
The younger Theodosius was born about the year 346. He was a native of Spain, but the exact place of his birth is uncertain (Cauca in Galicia according to Idatius and Zosimus, Italica according to Marcellinus). Pacatus and Claudian seem to claim for him at least a relationship to Trajan, of which, however, there is no satisfactory proof. He accompanied his father into Britain (368), and a little later distinguished himself by defeating the Sarmatians who had invaded Mcesia (374). On his father's death he retired to his native place, where he lived quietly till after the great battle of Adrianople (August 9, 378), when Gratian summoned him to share the empire. Theodosius was made Augustus at Sirmium, January 19, 379, and was assigned all the Eastern provinces, including Illyricum. It was a time of great peril for the Roman state. The Huns had just made their appearance on the western shores of the Black Sea, and, after over-throwing the great nation of the Ostrogoths, had driven the more southern Visigoths to take shelter within the empire. Valens had consented to receive them (376) on condition that they should deliver up their arms and surrender their children as hostages to be distributed throughout the cities of the East. The latter half of the compact was enforced, but not the former ; and the barbarians, left with-out any sustenance, began to plunder the open country. After their great victory at Adrianople they reached the walls of Constantinople, whence they were driven back by the valour of a band of Saracens. Meanwhile the Ostrogoths, the Taifali, the Huns, and the Alans had all crossed the Danube to share the spoils of the empire; and it was against this motley host that Theodosius had to contend. He appears to have gained some successes even before his elevation to the empire (Theodoret, v. 5, 6), and shortly after this retired to Thessalonica to organize his forces. He breathed courage into what remained of the Roman army, and summoned the very miners to his standard. But his chief reliance was placed in certain bodies of the Goths whom he had enrolled in his service. These, under their royal leader Modares, gained at least one decisive victory, probably in the course of 379. From theunchron-ological account of a later writer, Zosimus, to whom we owe almost all the details of Theodosius's early campaigns, we may infer that in the course of this year or the next Fritigern and his Visigoths were gradually driven across the Danube, where they seem to have met with the Ostro-goths who had shared their fate. For a time the united nations turned their energy against the Western empire, till they forced Gratian to grant them leave to settle in Pan-nonia and Moesia. Before setting out on their new journey they perhaps combined their forces to attack Athanaric, who had retreated with his section of the Visigoths into the wilds beyond the Danube at the time of the Hunnish invasion. Unable to withstand their onset, Athanaric offered his services to Theodosius, and was received into Constantinople with every mark of favour, 11th January 381. Fifteen days later he died, and was honoured by the emperor with a splendid funeral, while his followers faithfully discharged the duty of guarding the Danube.
In the two preceding years Thessaly and Macedonia had been swept by the barbarians. On one occasion the emperor himself barely escaped from their hands in a midnight attack which they had been induced to make by the sight of his blazing watchfires; on another the united forces of the Ostrogoths and Visigoths crossed the Danube with the design of pillaging Greece. In his efforts against the invaders Theodosius was ably seconded by his colleague Gratian, who despatched his Frankish officers Baudo and Arbogastes to drive the enemy out of Macedonia and Thessaly (380), and, while Theodosius lay sick at Thessalonica, made such terms with them as the latter emperor was glad to accept on his recovery. A little later, presumably towards the middle of 381, Promotus, Theodosius's lieutenant, inflicted a terrible defeat on a motley host that was attempting to cross the Danube. This was perhaps the decisive battle in the war; and we read that on October 3, 382, all the remaining Goths in the empire submitted to Theodosius. Many of them appear to have entered the Roman army as " fcederati"; and indeed, from the very commencement of his reign, Theodosius seems to have pursued a consistent policy of enrolling the Gothic warriors. At times they accepted his gifts while meditating treachery in their hearts; and Eunapius has preserved the story of how Fravitta, the leader of the faithful party, slew with his own hands his dishonest colleague Eriulf at a banquet in the emperor's own tent. Zosimus has charged Theo-dosius with burdening the provinces with excessive duties for the purpose of maintaining a host of useless barbarian officers, while the common soldiers were left unpaid. These barbarian troops, according to the same writer, often treated the Roman citizens with the utmost indignity, and on more than one occasion provoked a retaliation for which the emperor refused to see any excuse. They were not, however, all quartered in one place, but received into the legions ; while others were sent to Egypt. On the whole, it may be said that his policy of attaching the invaders to himself was the salvation of the empire; it was they who bore the brunt of the battle of the Frigidus; and the knowledge of the emperor's good faith towards the Teutonic auxiliaries in his service must have contributed largely to the defection of Eugenius's army on the same occasion.
In 383 Theodosius created his eldest son Arcadius Augustus. The same year saw the revolt of Maximus in Britain and the murder of Gratian (August 25, 383). For five years Theodosius consented to accept the usur-per as his colleague; but, when Maximus, flushed with success, attempted a few years later to make himself master of Italy, which, since the sudden death of Valen-tinian I. (17th November 375), had been governed under the name of his young son Valentinian II., Theodosius advanced against the invader and overthrew him near Aquileia (28th July 388). This victory was followed by the murder of Maximus and his son Victor, after whose death Theodosius conferred upon Valentinian II. all that part of the empire which his father had held. Theodosius is said to have been induced to take this campaign by his love for Valentinian's sister Galla, whom he now married. Meanwhile there had been fresh dangers from the Goths. In 386 another band of the Grcethingi or Ostrogoths, attempting to cross the Danube, was cut off by Promotus. The same general, in the course of the next two years, punished the barbarians who had deserted Theodosius at the beginning of the campaign against Maximus. Such signal services as these, though coupled with the fact that he had saved the emperor's life, did not prevent Promotus from falling a victim to the intrigues of the favourite Rufinus, who is charged by Zosimus with compassing the death of other noble men. If we may trust the evidence of the last-mentioned historian, from the end of the year 388 Theodosius resigned himself to gluttony and volup-tuous living, from which he was only roused by the news that, in the Western empire, Arbogastes the Frank had slain the young emperor Valentinian and set up the grammarian Eugenius in his stead (15th May 392).
Into the curious history of the short-lived pagan revival in the Western empire there is no need to enter here. Zosimus assures us that the tears of Galla threw the whole court into confusion ; but there can be little doubt that to a religious, if not superstitious, mind like that of Theodosius it might well have seemed that he was fighting the battles of God, as he led his army of the cross against an enemy on whose standard shone the image of Hercules (Theodoret, v. 24). His host consisted partly of Romans and partly of barbarians. Timasius was leader of the former, but under him was ranged the more renowned Stilicho ; the latter were led by Gainas the Goth and Saul the Alan. The engagement was fought near the river Frigidus, some thirty-six miles distant from Aquileia. On the first day Theodosius's barbarians, engaging with those of the hostile army, were almost destroyed, and the victory seemed to be with Eugenius. After a night of prayer, towards cock-crow the emperor was cheered by a vision of St Philip and St John, who, mounted on white steeds, promised him success. With the morning he received and accepted the offer of service on behalf of the enemy's ambush, and once more advanced to the conflict. But even so, the issue of the day was doubtful till, if we may trust the concurrent testimony of all the great contemporary church historians, a sudden gust of wind blew back the enemy's arrows on themselves. This was the turning-point of the battle : Eugenius was slain by the soldiers; and two days later Arbogastes committed suicide (Sep-tember 5-9, 394). From the north-eastern parts of Italy Theodosius passed to Rome, where he had his son Honorius proclaimed emperor under the guardianship of Stilicho. Thence he retired to Milan, where he died of dropsy (17th January 395), leaving the empire to be divided between his two sons Honorius and Arcadius,'Honorius becoming emperor of Rome and the West, Arcadius of Constan-tinople and the East.
Important, however, as the reign of Theodosius was from the political point of view, it is perhaps still more important from the theological. According to Sozomen, his parents were both orthodox Christians, according to the creed sanctioned by the council of Nicaea. It was not, however, till his illness at Thes-salonica that the emperor received baptism at the hands of Bishop Ascholius, whereupon, says the same historian, he issued a decree (February 380) in favour of the faith of St Peter and Pope Damasus of Borne. This was to be the true catholic faith; the adherents of other creeds were to be reckoned as heretics and punished. The great council of Constantinople, consisting of 150 orthodox and 36 Macedonian bishops, met in the following year, confirmed the Nicene faith, ordered the affairs of the various sees, and declared the bishop of Constantinople to rank next to the bishop of Rome. The emperor cannot be acquitted of the intoler-ance which marks edicts such as that depriving apostatizing Christians of the right of bequest. It was not till 389 or 390 that he issued orders for the destruction of the great idol of Serapis at Alexandria. Other edicts of an earlier or later date forbade the unorthodox to hold assemblies in the towns, enjoined the surrender of all churches to the catholic bishops, and overthrew the heathen temples " throughout the whole world." During the reign of Theo-dosius Gregory of Nazianzus was made bishop of Constantinople an appointment which he did not long retain. In 383 Theodosius called a new council for the discussion of the true faith. The orthodox, the Arians, the Eunomians, and the Macedonians all sent champions to maintain their special tenets before the emperor, who finally decided in favour of the orthodox party. He seems to have suffered the Novatians to hold assemblies in the city. Perhaps the most remarkable incident in the life of Theodosius from a personal point of view is the incident of his submission to the reprimands of Ambrose, who dared to rebuke him and refuse to admit him to the Lord's Supper till he had done public penance for suffering his Gothic auxiliaries to murder the townsmen of Thessa-lonica (390). Equally praiseworthy is the generous pardon that the emperor, after much intercession, granted to'the seditious people of Antioch, who, out of anger at the growing imposts, had beaten down the imperial statues of their city (387). When the Christians in the eastern part of the empire destroyed a Jewish synagogue and a church belonging to the Valentinians, Theodosius gave orders for the offenders to make reparation. Such impartial conduct drewforth a remonstrance from Ambrose, who, where the interests of his creed was concerned, could forget the common principles of justice. In a sermon preached before Theodosius he introduced the Deity Him-self holding an argument against Theodosius on the subject of his remissness, and the imperial penitent yielded to the eloquent bishop. So pliant a disposition rendered him very dear to the saint, who availed himself of his influence to counteract the efforts of Symmachus and the Roman senate for the restoration of the pagan rites at the altar of victory. "I loved the man," says St Ambrose, " who, putting off his kingly robes, mourned publicly in the church a sin to which the guile of others had exposed him, an emperor who thought it no shame to do an act of public penance that even private people would have blushed to perform." The inspired vision of the saint saw the deceased emperor received into heaven by his old colleague Gratian; while Maximus and Eugenius down in hell were already experiencing how grievous a sin it is to take up arms against lawful princes (Ambrose, De Obitu Theod.).
Theodosius was twice married(1) to zElia Flacilla, the mother of Arcadius (377-408) and Honorius (384-423); (2) to Galla (d. 394), the daughter of Valentinian I.
The chief authorities for the age of Theodosius are Ammianus Marcellinus,
Zosimus, Eunapius, and the ecclesiastical historians (Socrates, Sozomen, Theo-
doret). Much information may also be gleaned from the writings of St Ambrose,
St Gregory of Naziauzus, Isidore of Seville, and the orators Pacatus, Libanius,
Themistius. Of modern authorities Tillemont supplies an unrivalled collection
of facts drily collected from all contemporary or nearly contemporary sources;
he is specially useful for his synopses of the Theodosian laws. Clinton's Fasti
are the best guide for the chronology of the period. It is hardly necessary to
mention the brilliant account given by Gibbon, or, in later years, from the stand-
point of Italian history by Mr Hodgkin. (T. A. A.)