Question
What is the Synodicon of Orthodoxy?
Answer
The Synodicon of Orthodoxy proclaims the Orthodox faith and identifies the heresies of which the faithful should be wary. Originally written in 843 by Patriarch Methodius I for the Triumph of Orthodoxy over the Iconoclasts, it was expanded over the years and centuries that followed so that today it also includes those teachings of the Orthodox Church, which St. Gregory Palamas defended so admirably.
For more information, see also my Notes in Christopher Veniamin, ed., Saint Gregory Palamas: The Homilies (Dalton PA: 2022), p. 542-543, n. 91.