The Acts of the CouncilofChalcedon together with the imperial and papal correspondence before and after the council as part of the corpus are one of the most important contemporary sources for the historical events of the year 451 that has
During the reconquest of the barbarian-held western provinces, in his effort to establish religious unity in the Byzantine Empire, Emperor Justinian — his powers extended — issued secular decrees to sanction the decisions of bishops, making his own creed compulsory for Catholics. In the 530s he was constantly faced with the dilemma of whether to join the western church, which honoured the decisions of the Council of Chalcedon, or to reconcile himself to the Monophysites, popularised by Alexandria. As Theodora had an affinity for the Monophysites, Justinian changed his attitude several times. However, both his violent methods and his frequent replacement of clerical leaders contributed to the fact that instead of an agreement, an ultimate schism occurred between the two groups.
September 451 raiding the Balkans and compelling the Byzantine emperor Marcian to move a church council from Nicaea to Chalcedon 14 (Acts of the CouncilofChalcedon II: I: 1, 28; II: 2, 3; IV, 55), though admittedly these Huns could have been a contingent