The forces of Emperor Theodosius were fully committed in the West so the Huns moved unopposed until the end of 398 when the eunuch Eutropius gathered together a force composed of Romans and Goths and succeeded in restoring peace.

Arbogast immediately committed suicide after the defeat, while Eugenius was held for execution as a criminal, his head afterward being displayed in Theodosius ' camp.

Domnus's sentence, though revoked by Flavian, Patriarch of Constantinople, was confirmed by three episcopal commissioners to whom he and the emperor Theodosius II had committed the matter.

When the Eastern Emperor Theodosius heard the news of Valentinian's death, Arbogast, who was the magister militum and de facto ruler of Western Empire, informed him that the young emperor had committed suicide.

Arbogast, on the other hand, was able to escape the clutches of Theodosius I and fled into the Alps where he is said to have wandered alone for a couple days before realizing how hopeless he had become and committed suicide a few days after September 6, 394 in the noble Roman fashion.

He negotiated receiving recognition by the legitimate Augusti Valentinian II and Theodosius I and, when these negotiations failed, pressed the matter by proclaiming his son an Augustus, indicating an attempt to secure a succession.

Although much of the church hierarchy in the East had opposed the Nicene creed in the decades leading up to Theodosius ' accession, he managed to achieve unity on the basis of the Nicene creed.

Under Ambrose's major influence, emperors Gratian, Valentinian II and Theodosius I carried on a persecution of Paganism .< ref name = " MacMullen1984p100 "> MacMullen ( 1984 ) p. 100: ‘ The law of June 391, issued by Theodosius [...] was issued from Milan and represented the will of its bishop, Ambrose ; for Theodosius — recently excommunicated by Ambrose, penitent, and very much under his influence < sup > 43 </ sup > — was no natural zealot.

Theodosius, however, was unable to do much about Maximus due to his still inadequate military capability and he was forced to keep his attention on local matters.

In 386, Emperor Theodosius I began erecting a much larger and more beautiful basilica with a nave and four aisles with a transept ; the work including the mosaics was not completed until Leo I's pontificate ( 440 – 461 ).

“ He was by nature kind, affable, easily led ... Not only was he foolishly kind ; he was careless, and often he was to neglect his duty in the administration of his Empire .” This lack of power that Theodosius exemplified led to Pulcheria taking on a much larger role of authority and influence in the Empire.

So much so, in fact, that in 380 CE Gratian sent Arbogast along with his magister militum Bauto to aid Theodosius I against the Goths and their leader Fritigern after they had pillaged and plundered areas of Macedonia and Thessaly that year and the year before.

At this point, Valentinian II began recognizing the extent to which Arbogast's authority had reached, and with Arbogast seemingly expressing his authority over him at will, Valentinian II began sending secret messages to both Theodosius I and Ambrose, Bishop of Milan, pleading for them to come to his aid, even so much as asking Ambrose for a baptism in fear that his death might come sooner than expected at the hands of Arbogast.

The Emperor Theodosius II and his wife Aelia Eudocia greatly respected the saint and listened to his counsels, while the Emperor Leo I paid respectful attention to a letter he sent in favour of the Council of Chalcedon.

Two days after Theodosius arrived in Constantinople, 24 November 380, he expelled the Homoiousian bishop, Demophilus of Constantinople, and surrendered the churches of that city to Gregory Nazianzus, the leader of the rather small Nicene community there, an act which provoked rioting.

Theodosius had just been baptized, by bishop Acholius of Thessalonica, during a severe illness, as was common in the early Christian world.

The emperor Theodosius the Great ordered the rebuilding of the synagogue at the expense of the rioters, including the bishop.

On his accession to the imperial throne, Theodosius offered to confirm Demophilus as bishop of the imperial city on the condition of accepting the Nicene Creed ; however, Demophilus refused to abandon his Arian beliefs, and was immediately ordered to give up his churches and leave Constantinople.

Damasus ' response repudiated Maximus summarily and advised Theodosius to summon a Council of Bishops for the purpose of settling various Church issues such as the schism in Antioch and the consecration of a proper bishop for the see of Constantinople.

Damasus condemned the translation of bishops from one see to another and urged Theodosius to " take care that a bishop who is above reproach is chosen for that see.

When Chrysostom arrived in Antioch, the bishop of the city had to intervene with Emperor Theodosius I on behalf of citizens who had gone on a rampage mutilating statues of the Emperor and his family.

Theodosius was threatened with excommunication by the bishop of Milan, Saint Ambrose for the massacre.

Emperor Theodosius I orders vengeance, despite the pleas of Ambrose, bishop of Milan, for mercy, and more than 7, 000 inhabitants are massacred by the Roman army.

By 729 Theodosius is believed to have become bishop of Ephesus.

By his unnamed wife, Theodosius III was the father of at least one son, Theodosius ( monastic name ), perhaps the bishop of Ephesus in 729 – after 754.

Meanwhile throughout the city of Amasea, although entry into the temples and holy places had been forbidden by the decree of Theodosius I ( 391 ), the festival of gift-giving when " all is noise and tumult " in " a rejoicing over the new year " with a kiss and the gift of a coin, went on all around, to the intense disgust and scorn of the bishop:

From the time of Theodosius I ( r. 379 – 395 ), the emperors no longer appear in the dignity of pontiff, but the title was later applied to the Christian bishop of Rome.

* Theodosius, bishop of Philadelphia, deposed at Council of Seleucia, 359

Through the intervention of John Chrysostom, soon after his elevation to the patriarchate of Constantinople in 398, and the influence of the emperor Theodosius I, Flavian was acknowledged in 399 as the sole legitimate bishop of Antioch.

A letter of Ambrose and his brother-prelates to Theodosius remonstrates against the acts of Nectarius as no rightful bishop, since the chair of Constantinople belonged to Maximus, whose restoration they demanded, as well as that a general council of Easterns and Westerns, to settle the disputed episcopate and that of Antioch, should be held at Rome.

Here he met Peter the Iberian, who had been ordained bishop of Gaza by Theodosius, the Non-Chalcedonian monk, during his usurpation of the patriarch of Jerusalem.

Edicts of the Emperor Theodosius II and of Valentinian III proclaimed the Roman bishop as " Rector of the whole Church ".

According to early Christian sources, bishop Theophilus of Alexandria was Nicene patriarch when the decrees of emperor Theodosius I forbade public observances of any rites but Christian.

At the death of Auxentius, the great St. Ambrose was elected bishop by the people of Milan ( 374-97 ), and was the guide of princes Gratian, Valentinian II, and Theodosius.

Theodosius was threatened with excommunication by Ambrose for the massacre of 7, 000 persons at Thessalonica in 390, after the murder of the Roman governor there by rioters.

* 380 – Edict of Thessalonica: Emperor Theodosius I, with co-emperors Gratian and Valentinian II, declare their wish that all Roman citizens convert to trinitarian Christianity.

* Ambrose retires to Milan ( residence of Theodosius I ) and refusing to celebrate a mass in the emperor's presence, until he repents for ordering the massacre in Thessalonica.

* February 27 – Edict of Thessalonica: Theodosius I, with co-emperors Gratian and Valentinian II, declare their wish that all Roman citizens convert to trinitarian Christianity, in accordance with the patriarchs of Rome and Alexandria, implicitly rejecting the Arianism of the patriarch of Constantinople as heretical.

Theodosius I retreats to Thessalonica and leaves Gratian control over the Western Roman Empire.

Solidus ( coin ) | Solidus minted in Thessalonica to celebrate Valentinian III's marriage to Licinia Eudoxia, daughter of the Eastern Roman Empire | Eastern Emperor Theodosius II.

Valentinian II and Justina fled to Theodosius in Thessalonica.

Maximus withdrew to Thessalonica to lay his cause before the emperor Theodosius I.

* 380-Edict of Thessalonica issued by Theodosius I makes Christianity the State church of the Roman Empire

Towards the end of the century, Bishop Ambrose of Milan made the powerful Emperor Theodosius do penance for several months after the massacre of Thessalonica before admitting him again to the Eucharist.

* February 380: Emperor Theodosius I issues an edict, De Fide Catolica, in Thessalonica, published in Constantinople, declaring Catholic Christianity as the state religion of the Roman Empire.

Solidus minted in Thessalonica to celebrate the marriage of Valentinian III to Licinia Eudoxia, daughter of the Eastern Emperor Theodosius II.

For over two generations, since Constantine I had recognized the Christian faith and Theodosius I had made it the official religion of the State with the Edict of Thessalonica, conflict simmered between the Roman Senate, many of whom were not Christian, and the emperors in Constantinople and Milan who officially subscribed to Christian teachings.

In that year the Diocese of Pannonia ( Illyricum occidentale, " Western Illyricum ") was again added to Italy as the " Diocese of Illyricum ", while Macedonia and Dacia ( Illyricum orientale, " Eastern Illyricum ") were ruled briefly directly by Theodosius I from Thessalonica.

Only after the death of Theodosius in 395 and the permanent division of the Empire did the Illyricum assume the permanent form which appears in the Notitia, incorporating the dioceses of Macedonia and Dacia, with Thessalonica as capital.