Held in Nicea, Asia Minor in 787. Under Empress Irene. 367 Bishops were present.
The Iconoclast Controversy
It centered around the use of icons in the Church and the controversy between the iconoclasts and iconophiles. The Iconoclasts were suspicious of religious art; they demanded that the Church rid itself of such art and that it be destroyed or broken (as the term "iconoclast" implies).
The iconophilles believed that icons served to preserve the doctrinal teachings of the Church; they considered icons to be man's dynamic way of expressing the divine through art and beauty. The Iconoclast controversy was a form of Monophysitism: distrust and downgrading of the human side.
The Council's Proclamation
"We define that the holy icons, whether in color, mosaic, or some other material, should be exhibited in the holy churches of God, on the sacred vessels and liturgical vestments, on the walls, furnishings, and in houses and along the roads, namely the icons of our Lord God and Savior Jesus Christ, that of our Lady the Theotokos, those of the venerable angels and those of all saintly people. Whenever these representations are contemplated, they will cause those who look at them to commemorate and love their prototype. We define also that they should be kissed and that they are an object of veneration and honor (timitiki proskynisis), but not of real worship (latreia), which is reserved for Him Who is the subject of our faith and is proper for the divine nature, ... which is in effect transmitted to the prototype; he who venerates the icon, venerated in it the reality for which it stands."
Defenders of Orthodoxy
St. John of Damascus (675-745)
John Mansur was educated at the Caliphate Court in Damascus. He held a position comparable to that of a Prime Minister. He was a devout Orthodox Christian. He entered the Monastery of St. Sabbas in Palestine, where he wrote many poems, hymns and treaties, one of which is called "An Exact Exposition of the Orthodox Faith." This work is a systematic theological summary of all the basic doctrines of the first seven centuries, a monumental work which became a classic in Orthodox Theology.
The Triumph of Orthodoxy
An Endemousa (Regional) Synod was called in Constantinople in 843. Under Empress Theodora. The veneration of icons was solemnly proclaimed at the St. Sophia's Cathedral. Monks and clergy came in procession and restored the icons in their rightful place. The day was called "Triumph of Orthodoxy." Since that time, this event is commemorated yearly with a special service on the first Sunday of Lent, the "Sunday of Orthodoxy."
Read about the other Ecumenical Councils: