 This rite commemorates the end of Byzantine Iconoclasm—the last great heresy to trouble the church (all subsequent heresies—so far—merely being restatements in one form or another of previous errors)—at the Council of Constantinople in 843.The "Synodicon", or decree, of the council was publicly proclaimed on this day, including an anathema against not only Iconoclasm but also of previous heresies.The "Synodicon" continues to be proclaimed annually, together with additional prayers and petitions in cathedrals and major monasteries throughout the Eastern Orthodox Churches.