PERSON INVOLVED
IMPORTANT CONTRIBUTION
1st Council of Nicea
Roman Emperor Constantine the Great with Pope Saint Sylvester I
The bold text in the profession of faith of the 318 fathers constitutes, according to Tanner "The additions made by the council to an underlying form of the creed", and that the underlying creed was most likely "derived from the baptismal formula of Caesarea put forward by the bishop of that city Eusebius" or that it "developed from an original form which existed in Jerusalem or at any rate Palestine". "
Constantinople 1
Theodosius I, Pope Saint Damasus I
The council of Constantinople enacted four disciplinary canons: against the Arian heresy and its sects (can. 1), on limiting the power of bishops within fixed boundaries (can. 2), on ranking the see of Constantinople second to Rome in honour and dignity (can. 3), on the condemnation of Maximus and his followers (can. 4). Canons 2-4 were intended to put a stop to aggrandisement on the part of the see of Alexandria.
Ephesus
Saint Cyril of Alexandria, Pope Saint Celestine I
John's profession of faith was accepted by Cyril and became the doctrinal formula of union. It is included here, together with Cyril's letter in which he at some length praises John's profession and accepts it, adding to it some explanation about his own expressions; this letter is mentioned in the definition of Chalcedon. Shortly afterwards, probably in 436, Nestorius was definitely sent into exile by the emperor .
Chalcedon
Saint Pulcheria
The "Definition of the faith" was passed at the council's fifth session, and was solemnly promulgated at the sixth session in the presence of the emperor and the imperial authorities. The formula accepted in the decree is: Christ is one in two natures. This is in agreement with Leo's letter to Flavian of Constantinople, and Leo's letter is expressly mentioned in the Definition of the faith .
Constantinople 2
Justinian I
The Second Council in Constantinople