The Sunday of Orthodoxy is the first Sunday of Great Lent. The dominant theme of this Sunday since 843 has been that of the victory of the icons. In that year the iconoclastic controversy, which had raged on and off since 726, was finally laid to rest, and icons and their veneration were restored on the first Sunday in Lent. Ever since, this Sunday has been commemorated as the "Triumph of Orthodoxy."
At the conclusion of the Divine Liturgy, a service is conducted in commemoration of the affirmations of the Seventh Ecumenical Council in 787 and the restoration of the use of icons in 843. Orthodox faithful carry icons in a procession, followed by a reading of excerpts from the Affirmation of Faith of the Seventh Ecumenical Council and the singing of the Great Prokeimenon.