The Canonical Epistle of Our Holy Father Among the Saints, Cyril, Archbishop of Alexandria, on the Hymns. 607
This letter contains a complaint of one, Peter, deposed from his See, yet retaining the character of a bishop, who thought his cause good, but complains that he had not time and opportunity given him for his defence; and that whatever he had, was taken away from him. He desires Domnus, who was a Metropolitan, that he would call a synod, and let him have a hearing; and that such bishops as Peter suspected of prejudice against him should not be permitted to be his judges. He thinks it very hard, that not only what belonged to the Church, but every thing else was taken from him; and complains that all bishops were called to account for every thing they received, whether from the Church, or by any other means. Peter had indeed signed an instrument of resignation; but Cyril says, that he was terrified into it; and that he would have no such resignation be of force except he that made it deserved deposition.
Johnson gives the date of this as about the year 412 a.d.