1. First Council of Nicaea, Turkey, 325
Attended by more than 300 bishops. Condemned Arian Heresy, which denied the divinity of Christ. Set the date for Easter. Declared that God the Father and God the Son were of the same substance.

2. First Council of Constantinople, Turkey, 381
Attended by 150 bishops. Completed the Nicene Creed.

3. Council of Ephesus, Turkey, 431
Attended by 200 bishops. Condemned Nestorius, bishop of Constantinople, for teaching heresy. Defined Theotokos (Bearer of God) as the title of Mary, mother of the Son of God made Man.

4. Council of Chalcedon, Turkey, 451
Attended by about 600 bishops. Declared that Christ is one Person with two distinct natures, divine and human. This was proposed by Pope Leo I, and the response of the bishops was "This we all believe. Peter has spoken through Leo."

5. Second Council of Constantinople, Turkey, 553
Attended by 165 bishops. Condemned Nestonian Heresy.

6. Third Council of Constantinople, Turkey, 680-681
Attended by 160 bishops. Restated the teaching of the Council of Chalcedon (451), and condemned some false teachings.

7. Second Council of Nicaea, Turkey, 787
Declared that images could be set up and could be given honor or veneration, but not worship, since worship belongs to God alone. Iconoclasm (image-breaking) was condemned.

8. Fourth Council of Constantinople, Turkey, 869-870
Attended by more than 100 bishops. Excommunicated Photius, Patriarch of Constantinople, which caused further tension between East and West.


*******

Eastern General Councils
(325 - 870)

In the first millennium after Christ, the Church held its first eight General (Ecumenical) Councils (GCs) in the East in various places, now all part of present-day Turkey. Subsequently the General Councils convened in the West.

A summary of each of the eight GCs is given below; click on the associated hyperlink for a detailed account.