Councils
The councils that defined Christian doctrine — Ecumenical councils received by the whole Church before the great splits, plus the regional and denominational councils that followed. Each described in its own decisions, attendees, and creeds produced.
Ecumenical Councils
7
325 ADFirst Council of Nicaea
The first ecumenical council. It answered Arianism — the teaching that the Son was a created being, exalted but not eternal — by confessing that the Son is of one substance with the Father, true God of true God. It also set a common date for Easter and issued twenty canons.
381 ADFirst Council of Constantinople
The second ecumenical council. It completed the Church's confession of the Trinity by affirming the full deity of the Holy Spirit, and gave the Nicene Creed the expanded form recited in the liturgy to this day.
431 ADCouncil of Ephesus
The third ecumenical council. It confessed the unity of Christ's person against the teaching associated with Nestorius, and affirmed the title Theotokos — God-bearer — for Mary, a statement about who Christ is.
451 ADCouncil of Chalcedon
The fourth ecumenical council. It defined that Christ is one person in two natures — fully divine and fully human — united 'without confusion, without change, without division, without separation.' The Chalcedonian Definition is the touchstone of orthodox Christology.
553 ADSecond Council of Constantinople
The fifth ecumenical council. It addressed the long controversy over the 'Three Chapters' — certain writings perceived as Nestorian — and reaffirmed Chalcedon while clarifying that it was to be read in continuity with Cyril of Alexandria.
680 ADThird Council of Constantinople
The sixth ecumenical council. It confessed that Christ has two wills — divine and human — corresponding to his two natures, the human will moving in free and full accord with the divine.
787 ADSecond Council of Nicaea
The seventh and last of the councils received as ecumenical by the East. It addressed the iconoclast controversy, distinguishing the veneration shown to images from the worship due to God alone.