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Roman Empire Βασιλεία Ῥωμαίων (Ancient Greek) Imperium Romanum (Latin)
379–457
Chi Rho (seeByzantine insignia)
The territory of the Eastern Roman Empire, with theWestern Roman Empire depicted in orange, at the beginning of Theodosius I's reign.
Capital	Constantinople
Common languages	Latin,Greek
Government	Monarchy
Emperor
• 379–395	Theodosius I
• 395–408	Arcadius
• 408–450	Theodosius II
• 450–457	Marcian
History
• accession ofTheodosius I	19 January 379
• death ofMarcian	January 457
Preceded by Succeeded by Byzantine Empire under the Constantinian and Valentinianic dynasties Byzantine Empire under the Leonid dynasty

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TheEastern Roman Empire was ruled by theTheodosian dynasty from 379, the accession ofTheodosius I, to 457, the death ofMarcian. The rule of the Theodosian dynasty saw the final East-West division of theRoman Empire, betweenArcadius andHonorius in 395. Whilst divisions of the Roman Empire had occurred before, the Empire would never again be fully reunited. The reign of the sons of Theodosius I contributed heavily to the crisis that under the fifth century eventually resulted in thecomplete collapse of the western Roman court.

The Eastern Empire was largely spared the difficulties faced by the West in the third and fourth centuries, due in part to a more firmly established urban culture and greater financial resources, which allowed it to placate invaders withtribute and pay foreignmercenaries. Throughout the fifth century, various invading armies overran the Western Empire but spared the east.

The Theodosian dynasty also ruled theWestern Roman Empire from 392 to 455 AD.

Theodosius I was granted rule of the Eastern Roman provinces by the Western Augustus,Gratian of theValentinianic dynasty, due to his having inherited the entire Empire from his predecessorValens in 378 and to lack of ability to rule over both halves. Gratian would continue to rule the Western Roman Empire until 383. After the deaths of Gratian and his successor Valentinian II, Theodosius became the last emperor to rule over both theeastern and thewestern halves of theRoman Empire 392-395.

Theodosius is also remembered for making a series of decrees (seeEdict of Thessalonica) that essentially codified Nicene Christianity as the officialstate church of the Roman Empire.^[1][2] Theodosius dissolved the order of theVestal Virgins inRome, banned the pagan rituals of theOlympics in Ancient Greece and did nor punish nor prevent the destruction of antique Hellenistic temples, such as theTemple of Apollo inDelphi.

With the death of Theodosius in 395, the Roman Empire was divided once more between his two sons.Arcadius, the older son, inherited the East and the imperial capital of Constantinople, andHonorius inherited theWest. The Empire would never be reunited again, though Eastern Roman emperors, beginning withZeno, would claim the de jure united title afterJulius Nepos' death in 480 AD.

Arcadius was a weak ruler, dominated by a series of figures behind the throne as he was more concerned with appearing to be a pious Christian than he was with political and military matters. The first such figure,Rufinus, engendered intense competition with the counterpart of Western Emperor Honorius,magister militum of half-Vandal originFlavius Stilicho, who might have had him assassinated in 395 AD. Later figures in actual power would include consulEutropius risen from eunuch, generalGainas of Gothic origin, his wifeAelia Eudoxia, the PatriarchJohn Chrysostom andPraetorian PrefectAnthemius.

Theodosius II, sometimes nicknamed "the Younger",^[3] became Eastern Roman Emperor at the age of seven following the death of his father Arcadius in 408. Praetorian Prefect Anthemius continued to act as a power behind the throne, during whose tenure theTheodosian walls ofConstantinople were completed.

The older sister of Theodosius,Pulcheria, was proclaimedAugusta and became regent in 414 AD. Though the regency ended in 416 and Theodosius becameAugustus himself, Pulcheria remained a strong influence within the government. Influenced by Pulcheria and fueled by an increasing devotion to Christianity, Theodosius went towar against the Sassanid Empire in the early 420s, on the pretext of defending Christians from persecution. He was forced to accept a stalemate however, as theHuns were marching on Constantinople. The wars with the Huns were usually composed by Hunnic raids being followed by significant payments by the Eastern Empire so that the Huns would remain at peace with the Romans.

The death of Honorius of the West in 423 led Theodosius to supporting and eventually installingValentinian III as Western Emperor in 425. To strengthen ties between East and West,Licinia Eudoxia, daughter of Theodosius, was betrothed to Valentinian.

Theodosius died in 450 as the result of a riding accident and was succeeded byMarcian, husband of his sister Pulcheria, as Eastern Emperor.

Marcian would reverse many of the actions taken by Theodosius II, particularly in terms of treaties with the Huns and in religious affairs. All Eastern Roman tributary payments toAttila ceased under Marcian while Attila was busy invading Italy. Marcian launched preemptive expeditions across theDanube into the Hunnic heartland, winning significant victories against them. The actions of Marcian, combined with famine in Italy, forced Attila to retreat back to theHungarian plains where he would die in 453. After the death of Attila, Marcian would settle many formerly hunnic vassal tribes within Eastern Roman lands asfoederati, taking advantage of the fall of the Hunnic empire.

He would be succeeded byLeo I, the first Emperor of theLeonid dynasty.

• Family tree of Byzantine emperors

• States and territories established in the 370s
• States and territories disestablished in the 5th century
• 5th century in the Byzantine Empire
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