On the Sunday that falls from the 13th to the 19th of the present month of July, we chant the Service to the Holy and God-bearing Fathers who came together in the Seven Ecumenical Councils.
Originally this Sunday commemorated only the Holy Fathers of the Fourth Ecumenical Council which took place in 451 A.D., yet at some point it came to encompass the Seven Ecumenical Councils, that is:
A) The First Ecumenical Council, of the 318 Fathers who assembled in Nicaea in 325 to condemn Arius, who denied that the Son of God is consubstantial with the Father; the Fathers of the First Council also ordained that the whole Church should celebrate Pascha according to the same reckoning;
B) The Second Ecumenical Council, of the 150 Fathers who assembled in Constantinople in 381 to condemn Macedonius, Patriarch of Constantinople, who denied the Divinity of the Holy Spirit;
C) The Third Ecumenical Council, of the 200 Fathers who assembled in Ephesus in 431, to condemn Nestorius, Patriarch of Constantinople, who called Christ a mere man and not God incarnate;
D) The Fourth Ecumenical Council, of the 630 who assembled in Chalcedon in 451, to condemn Eutyches, who taught that there was only one nature, the divine, in Christ after the Incarnation, and Dioscorus, Patriarch of Alexandria, who illegally received Eutyches back into communion and deposed Saint Flavian, Patriarch of Constantinople, who had excommunicated Eutyches;
E) The Fifth Ecumenical Council in 535, of the 165 who assembled in Constantinople for the second time to condemn Origen and Theodore of Mopsuestia, the teacher of Nestorius;
F) The Sixth Ecumenical Council in 680, of the 170 who assembled in Constantinople for the third time, to condemn the Monothelite heresy, which taught that there is in Christ but one will, the divine;
G) The Seventh Ecumenical Council in 787, of the 350 who assembled in Nicaea for the second time to condemn Iconoclasm.
Apolytikion in the Plagal of the Fourth Tone
You are greatly glorified, O Christ our God, who established our Fathers as luminaries upon the earth, and through them led us all to the true Faith. O Most compassionate, glory to You.