Marcian (/ˈmɑːrʃən/; Latin: Marcianus; Greek: Μαρκιανός Markianós; c. 392 – 27 January 457) was Roman emperor of the East from 450 to 457. Very little of his life before becoming emperor is known, other than that he was a domesticus (personal assistant) who served under the commanders Ardabur and his son Aspar for fifteen years. After the death of Emperor Theodosius II on 28 July 450, Marcian was made a candidate for the throne by Aspar, who held much influence because of his military power. After a month of negotiations Pulcheria, Theodosius' sister, agreed to marry Marcian. Zeno, a military leader whose influence was similar to Aspar's, may have been involved in these negotiations, as he was given the high-ranking court title of patrician upon Marcian's accession. Marcian was elected and inaugurated on 25 August 450.

Solidus of Marcian
Roman emperor of the East
Reign25 August 450 – 27 January 457
PredecessorTheodosius II
SuccessorLeo I
Valentinian III (450–455)
Petronius Maximus (455)
Avitus (455–456)
Bornc. 392
Thrace or Illyria
Died27 January 457 (aged 65)[1]
SpousePulcheria (450–453)
IssueMarcia Euphemia
DynastyTheodosian dynasty
ReligionChalcedonian Christianity

Marcian reversed many of the actions of Theodosius II in the Eastern Roman Empire's relationship with the Huns under Attila and in religious matters. Marcian almost immediately revoked all treaties with Attila, ending all subsidy payments to him. In 452, while Attila was raiding Italy, then a part of the Western Roman Empire, Marcian launched expeditions across the Danube into the Great Hungarian Plain, defeating the Huns in their own heartland. This action, accompanied by the famine and plague that broke out in northern Italy, allowed the Western Roman Empire to bribe Attila into retreating from the Italian peninsula.

After Attila's death in 453, Marcian took advantage of the resulting fragmentation of the Hunnic confederation by settling Germanic tribes within Roman lands as foederati ("federates" providing military service in exchange for benefits). Marcian also convened the Council of Chalcedon, which declared that Jesus had two "natures": divine and human. This led to the alienation of the population of the eastern provinces of Syria and Egypt, as many of them were miaphysites, rejecting the new official Christology. Marcian died on 27 January 457, leaving the Eastern Roman Empire with a treasury surplus of seven million solidi coins, an impressive achievement considering the economic ruin inflicted upon the Eastern Roman Empire by the Huns and Theodosius' tribute payments. After his death, Aspar passed over Marcian's son-in-law, Anthemius, and had a military commander, Leo I, elected as emperor.