Although the western Emperor Gratian held orthodox belief in the Nicene creed, the younger Valentinian II, who became his colleague in the Empire, adhered to the Arian creed.

After the death in 392 of Valentinian II, whom Theodosius had supported against a variety of usurpations, Theodosius ruled as sole Emperor, appointing his younger son Honorius Augustus as his co-ruler for the West ( Milan, on 23 January 393 ) and by defeating the usurper Eugenius on 6 September 394, at the Battle of the Frigidus ( Vipava river, modern Slovenia ) he restored peace.

Olybrius married Placidia, younger daughter of Western Emperor Valentinian III and of his wife Licinia Eudoxia, thus creating a bond between a member of the senatorial aristocracy and the House of Theodosius.

The law was promulgated and he married Justina, by whom he had Valentinian the younger.

Placidia was the younger daughter of Emperor Valentinian III, who planned to marry her to Majorian ( 450 ca .).

Her younger brother, Valentinian III, was her full brother.

Oost notes that she accompanied her mother and younger brother as they set sail for Constantinople in Spring of 423, and that Honoria was with them when they joined the expeditionary force at Thessalonia in the Summer of 424 that would restore Galla Placidia and Valentinian to power in the West.

Galla Placidia was Valentinian III's mother and a younger, paternal half-sister of Arcadius.

With his younger half-brother Valentinian II as his nominal co-ruler.

This was done with ease on behalf of Arbogast and with the disposal of both Maximus and Victor, Theodosius I was able to give control over the West to Valentinian II, the younger son of Valentinian I.

He was given the eastern half of the empire by his brother Valentinian I after the latter's accession to the throne.

Valens and his brother Valentinian were both born in Cibalae ( in present-day Croatia ) into an Illyrian family in 328 and 321 respectively.

Valentinian felt that he needed help to govern the large and troublesome empire, and, on 28 March of the same year, appointed his brother Valens as co-emperor in the palace of Hebdomon.

* Spring – Justa Grata Honoria, eldest sister of emperor Valentinian III, sends her ring to Attila the Hun in an effort to escape a marriage being forced upon her by her brother.

* March 28 – Valens, brother of Valentinian I, is appointed co-emperor ( Augustus ) in the palace of Hebdomon ( Turkey ).

In 383 as commander of Britain, he usurped the throne against emperor Gratian ; and through negotiation with emperor Theodosius I the following year he was made emperor in Britannia and Gaul-while Gratian's brother Valentinian II retained Italy, Pannonia, Hispania, and Africa.

In 449, Attila received a message from Honoria, Valentinian III ’ s sister, offering him half the western empire if he would rescue for from an unwanted marriage that his brother was forcing her into.

Upon the death of Valentinian in 375, Gratian's brother Valentinian II was declared emperor by his father's soldiers.

Upon becoming emperor he made his brother Valens his co-emperor, giving him rule of the eastern provinces while Valentinian retained the west.

Valentinian selected his brother Valens as co-Augustus at Constantinople on 28 March 364.

Valentinian I becomes emperor and splits the empire with his brother Valens.

He was soon succeeded by Valentinian I, who named his brother Valens Emperor of the East.

Valentinian I was the twice-married brother of Valens ; his first wife Marina Severa bore him one son ( Gratian, whose first wife was Constantia, the daughter of Constantius II ), and his second wife Justina ( the widow of Magnentius ) bore him two children, a daughter ( Galla, the second wife of Theodosius I ; see below ) and a son ( Valentinian II ).

The sarcophagus to the right is attributed to Galla's son, Emperor Valentinian III, or to her brother, Emperor Honorius.

His brother in law, Maximinus was close to the emperor Valentinian I and was able to have Valentinus ' sentence commuted from execution to exile and he was sent to Roman Britain.

** Valentinian I's brother Valens ( 364-378 )

It was at this point when Arbogast joined the Roman imperial military service under the command of the emperor Gratian, son of Valentinian I and elder brother to Valentinian II, in the Western Roman Empire.

From 364 to 375, the Roman Empire was governed by two co-emperors, the brothers Valentinian I and Valens ; when Valentinian died in 375, his sons, Valentinian II and Gratian, succeeded him as rulers of the Western Roman Empire.

While Valentinian had enjoyed a successful military career prior to his appointment as emperor, Valens apparently had not.

* Law of Valentinian I and Valens bans marriages between Romans and barbarians under penalty of death.

* An edict issued by Valentinian I and Valens bans the importation of wine and olive oil from areas controlled by the barbarians.

* Valentinian I rules from Caledonia ( Scotland ) to the Rhine frontier the Western Roman Empire and Valens reigns from the Danube to the Persian border the Eastern Roman Empire.

Valens resided in Constantinople, while Valentinian ’ s court was at Milan.

The last traces of Emperors being at the same time chief pontiffs are found in inscriptions of Valentinian I, Valens, and Gratian ( Orelli, Inscript.

Under the Romans the town was known as Colonia Aurelia Cibalae and was the birthplace of Roman emperors Valentinian I and Valens.

The box contained about 600 Roman gold coins dating to the reigns of Valens and Valentinian I ( reigned 364 – 375 ), Gratian ( 375 – 383 ), Theodosius I ( 378 – 395 ), Arcadius ( 395 – 408 ), and Honorius ( 393 – 423 ).

Anne Roes found it on coins of Constantius II, Valentinian, Jovian, Gratianus, Valens, Arcadius, Constantine III, Jovinus, Theodosius I, Eugenius and Theodosius II, though she searched only coins at the British Museum.

Another was, according to a scholium in the Palatine Manuscript ( the most important source for our knowledge of Greek epigram ), written in the reign of the joint emperors Valentinian and Valens ( 364-375 ).

In the same year he delivered an oration at Constantinople, in honour of the accession of Valentinian I and Valens, in the presence of the latter.

His next orations are to the young Valentinian II upon his consulship, 369, and to the senate of Constantinople, in the presence of Valens, in honour of the peace granted to the Goths, 370.

Other notable people from these areas in this period included the Christian Jerome, Saint Marinus ( builder of San Marino ), emperors Valentinian I and Valens, and Pope John IV.

The brothers Valens ( r. 364 – 378 ) and Valentinian I ( r. 364 – 375 ) energetically tackled the threats of barbarian attacks on all the Western frontiers and tried to alleviate the burdens of taxation, which had risen continuously over the previous forty years ; Valens in the East reduced the tax demand by half in his fourth year.