In 359, the Roman Emperor Constantius II requested a church council, at Constantinople, of both the eastern and western bishops, to resolve the split at the Council of Seleucia. According to Socrates Scholasticus, only about 50 of the Eastern bishops, and an unspecified number of the western ones, actually attended.
Acacius of Caesarea declared that the Son (Jesus Christ) was similar to the Father (God) "according to the scriptures," as in the majority decision at the Council of Ariminum and close to the minority at the Council of Seleucia. Basil of Ancyra, Eustathius of Sebaste, and their party declared that the Son was of similar substance to the Father, as in the majority decision at Seleucia, a position known as homoiousia. Maris of Chalcedon, Eudoxius of Antioch, and the deacons Aëtius and Eunomius declared that the Son was of a dissimilar substance from the Father, a position known as anomoeanism or heteroousia.
The Heteroousians defeated the Homoiousians in an initial debate, but Constantius banished Aëtius, after which the council, including Maris and Eudoxius, agreed to the homoian creed of Ariminum with minor modifications.
After the Council of Constantinople, the homoiousian bishop Acacius deposed and banished several homoousian bishops, including Macedonius I of Constantinople, Basil, Eustathius, Eleusius of Cyzicus, Dracontius of Pergamum, Neonas of Seleucia, Sophronius of Pompeiopolis, Elpidius of Satala and Cyril of Jerusalem.
At the same time, Acacius also deposed and banished the Anomoean deacon Aëtius.
The resulting creed read:
We believe in one God the Father Almighty, of whom are all things. And in the only-begotten Son of God, begotten of God before all ages, and before every beginning; through whom all things visible and invisible were made: who is the only-begotten born of the Father, the only of the only, God of God, similar to the Father who begat him, according to the Scriptures, and whose generation no one knows but the Father only that begat him. We know that this only-begotten Son of God, as sent of the Father, came down from the heavens, as it is written, for the destruction of sin and death: and that he was born of the Holy Spirit, and of the Virgin Mary according to the flesh, as it is written, and conversed with his disciples; and that after every dispensation had been fulfilled according to his Father's will, he was crucified and died, and was buried and descended into the lower parts of the earth, at whose presence hades itself trembled: who also arose from the dead on the third day, again conversed with his disciples, and after the completion of forty days was taken up into the heavens, and sits at the right hand of the Father, whence he will come in the last day, the day of the resurrection, in his Father's glory, to requite every one according to his works. [We believe] also in the Holy Spirit, whom he himself the only-begotten of God, Christ our Lord and God, promised to send to mankind as the Comforter, according as it is written, "the Spirit of truth;" whom he sent to them after he was received into the heavens.
But since the term ousia [substance or essence], which was used by the fathers in a very simple and intelligible sense, but not being understood by the people, has been a cause of offense, we have thought proper to reject it, as it is not contained even in the sacred writings; and that no mention of it should be made in future, inasmuch as the holy Scriptures have nowhere mentioned the substance of the Father and of the Son. Nor ought the "subsistence" of the Father, and of the Son, and of the Holy Spirit to be even named. But we affirm that the Son is similar to the Father, in such a manner as the sacred Scriptures declare and teach. Let therefore all heresies which have been already condemned, or may have arisen of late, which are opposed to this exploitation of the faith, be anathema.
The Greek text:
? ?, , · ? ?, ? ?· ' ?, · ? , , ? ?, ? ? · , ? . ? ? ?, , ?, , ?· ? , ? , , ? ?· ? ? , , ?, ?, ? · ? ? ? ?. , ? ?· , ? , , ? ? ?, ? ? ? . , ? ? ? ? ?, ? ? ?, ? ?, ? , « ·» ? ?, ? .
«,» ? ? , ? , ? , ?, , ? ? ?. ? «» ? ? . ? ? , ?. , , ? , ? , ? ?.
Heortasius of Sardis, Dracontius of Pergamum, Silvanus of Tarsus, Sophronius of Pompeiopolis, Elpidius of Satala, Neonas of Seleucia, and Saint Cyril of Jerusalem were all exiled for their part in the Council of Seleucia the year before. Officially:
It is probable that Acacius, using his imperial connections, was ridding himself of longstanding enemies especially Cyril of Jerusalem.