Editing Marcian (section)

===Relationship with the Western Roman Empire===
Marcian was elected without any consultation with the Western Roman Emperor [[Valentinian III]], a clear indication of further separation between the Eastern and Western Roman Empires than before his reign.{{sfn|Gallagher|2008|p=243}}{{sfn|Lee|2001|p=42}} Valentinian would later recognize Marcian as the Eastern Roman Emperor, although the date of this recognition is disputed; Lee states that Valentinian recognized Marcian in March 452,{{sfn|Lee|2001|p=43}} whereas historian [[Timothy E. Gregory]] states that Marcian was recognized by Valentinian on 30 March 451.{{sfn|Kazhdan|1991}} Marcian{{'}}s appointment marked a further stage of separation between the Eastern and Western Roman Empires.{{sfn|Gallagher|2008|p=243}} One source, [[John of Antioch (chronicler)|John of Antioch's]] {{lang|la|Excerpta de insidiis}}, even suggest that Valentinian would have attempted to depose Marcian, but for Aetius{{'}} opposition.{{sfn|Lee|2001|p=43f}} Valentinian also did not recognize the Eastern Roman consuls for 451 or 452.{{sfn|McEvoy|2013|p=290, note 84}} The Western Roman chronicler [[Hydatius]] suggests that Marcian made Eastern Roman troops available to Valentinian to repel the Huns, confusingly led by a man named Aetius, which may simply be a muddling of Aetius' campaign against Attila and Marcian's campaign against the Huns on the Danube.{{sfn|McEvoy|2013|p=294}}

When Marcian granted part of Pannonia to the Ostrogoths, and the [[Tisza]] region to the Gepids, he was accused of encroaching upon the border of Western Roman land.{{sfn|Grant|1985|p=307}} Marcian avoided involving himself with the affairs of the Western Roman Empire when possible. When the Vandals [[Sack of Rome (455)|sacked Rome]] in 455, after [[Petronius Maximus]] assassinated Valentinian&nbsp;III and broke an [[engagement]] treaty with the Vandals, Marcian did not respond violently, possibly because of the influence of Aspar. He merely sent an envoy demanding that the Vandals return the [[Dowager Empress]], [[Licinia Eudoxia]] and her daughters by Valentinian III, [[Placidia]] and [[Eudocia (daughter of Valentinian&nbsp;III)|Eudocia]].{{sfn|Nathan|1998}} A likely false account is given that Marcian, while captured by the Vandals in his youth, was shaded by an eagle while the other prisoners suffered the hot sun. According to this account, the Vandal King Gaiseric recognized that Marcian would later be emperor. In exchange for being released, he made Marcian pledge not to attack the Vandals should he become emperor.{{efn|name=A|Propaganda involving the story of an eagle blocking the sun, and another figure recognizing they would be emperor, was used by both Byzantine emperors [[Philippicus]] and [[Basil&nbsp;I]].{{sfn|Lilie|2014|p=193}}}} This account originates from [[Priscus]], who served as an advisor to Marcian's confidant, Euphemius. Because of Euphemius' influence over foreign policy, some historians, such as [[Edward Arthur Thompson]], have suggested that this account was a part of official imperial propaganda, which was generated to excuse Marcian's lack of retribution towards the Vandals, and quell any discontent.{{sfn|Thompson|1950|p=68}} Marcian made several diplomatic attempts to have the prisoners returned, before finally beginning to plan an invasion of the Vandal's territory shortly before his death.{{sfn|Clover|1978|pp=193–194}} The historian [[Frank Clover]] has suggested that this sudden reversal of policy was caused by the marriage of Eudocia to [[Huneric]], the son of Gaiseric, which led to such pressure from Eastern Roman elites that Marcian was forced to begin preparations for war to ensure the return of the hostages. Around this time, Marcian made peace with Lazica, which would allow him to direct his attention elsewhere. The East Roman historian [[Theodorus Lector]] speaks of Marcian's sudden reversal of policy, and Evagrius Scholasticus, a Roman historian writing a century after the event, states that the Vandals released Licinia Eudoxia, Placidia, and Eudocia to Marcian after he threatened them with war, in either late 456 or early 457.{{sfn|Clover|1978|p=194}}{{sfn|Mathisen|1981|p=243}}

Marcian did not recognize any Western Emperor after Valentinian, denying Petronius Maximus, now Western Emperor, when he sent an embassy requesting it, and similarly refusing to recognize [[Avitus]], who succeeded Maximus.{{sfn|Kazhdan|1991|p=1296}}{{sfn|Kazhdan|1991a|p=704}} Marcian's exact treatment of Avitus is debated. The Roman historian Hydatius states that in 455 Avitus sent ambassadors to Marcian "for the sake of unanimity of power," and that, "Marcian and Avitus make use of Roman power in concord". The exact usage of concord ({{lang|la|concordia}} in the original Latin) has led to debate among scholars. Some such as [[Thomas Hodgkin (historian)|Thomas Hodgkin]], [[J. B. Bury]], and [[William Bayless]] consider it grounds for the belief that Marcian may have recognized Avitus. Most scholars take a more conservative stance on it; [[Ernst Stein]] suggests that it is merely a reflection of West Roman propaganda, whereas [[Norman Baynes]] believes it indicates that Marcian was cordial to Avitus, neither hostile nor friendly.{{sfn|Mathisen|1981|p=237}}{{sfn|Baynes|1922|p=223}} Classicist [[Courtenay Edward Stevens]] interprets the phrase as meaning only that the meeting of the diplomats was amicable, rather than reflecting a relationship between the two states.{{sfn|Mathisen|1981|p=237}}

The historian [[Geoffrey Nathan]] suggests the fact that only two Western delegates attended the Council of Chalcedon points to a new level of Western Roman self-absorption in their own political and religious affairs. He mentions that the canon from this council delegating authority over the whole east to the See of Constantinople marks a religious separation. Authority over the Church in the Eastern Roman Empire would prove a point of contention between Rome and Constantinople, leading up to the [[East–West Schism]].{{sfn|Nathan|1998}}