The '''Robber Council of Ephesus''' was convoked by Emperor [[Theodosius II]] on [[August 8]], 449 for the purpose of adjudicating the findings of the council of November 448 chaired by [[Flavian the Confessor|Flavian of Constantinople]] that had [[deposition|deposed ]] and excommunicated the [[Archimandrite]] [[Eutyches ]] for refusing to admit the two natures of Christ. The council, under the chair of [[Dioscorus of Alexandria]] and support of Emperor [[Theodosius II]], found in favor of Eutyches and deposed Flavian of Constantinople.

When reports of the actions of the Dioscurus led council and the violent actions of his partisans reached Pope Leo he condemned the council and called it the ''Latrocinium'', a ''Robber Council'' and refused to recognize Anatolius as the lawful Bishop of Constantinople until he satisfactorily explained his belief. Theodosius, however, ignored the position of Leo. On [[July 28]], 450, the situation changed radically as Theodosius was killed in a horse accident and his sister Pulcheria returned to imperial power and married the general [[Marcian]], who became the new emperor. The empress and new emperor both opposed the teachings of Dioscurus and Eutyches. With the change in imperial leadership Anatolius and many other bishops now also condemned the teachings of Dioscurus and Eutyches. As a step to clarify the disputes Marician now called for a new council which was held in 451 in [[Chalcedon]].