The Feast of Orthodoxy (also known as the Sunday of Orthodoxy or the Triumph of Orthodoxy) is celebrated on the first Sunday of Great Lent (six Sundays before Pascha) in the liturgical calendar of the Eastern Orthodox Church and Eastern Catholic Church (Eastern Catholics of Byzantine rite). The Feast is kept in memory of the final defeat of Iconoclasm and the restoration of the icons to the churches.

Troparion, Tone II

We worship Thy immaculate Image, O Good One, and ask forgiveness of our sins, O Christ God; for of Thy own will Thou wast pleased to ascend the Cross in the flesh, to deliver from slavery to the enemy those whom Thou hadst created. Therefore we thankfully cry to Thee: Thou hast filled all things with joy, O our Saviour, by coming to save the world.

Kontakion, Tone VIII

The illimitable Word of the Father accepted limitations by incarnation from thee, O Mother of God; and He transformed our defiled image to its original state and transfused it with the divine beauty. But we confess and give thanks for our salvation, and we proclaim it by deed and word.