Isaac of Seleucia

The acts of the synod of 410 call Isaac bishop of Seleucia and Ctesiphon, catholicos and archbishop of all the East, and say that it was in his time that peace came to the churches of the Persian empire (Synodicon Orientale pp. 254–255). Together with Marutha of Maypherkat he had the letter of the bishops of the Roman East translated from Greek into Persian and read to the king, Yazdegerd I (Synodicon Orientale p. 256). When the canons of Nicaea were read to the assembled bishops he was the first to declare his acceptance and to promise his signature (Synodicon Orientale pp. 259–260).

The king’s officials told the synod that Isaac had been confirmed by the king as head of the Christians of the East, and that those whom he and Marutha appointed were to be obeyed (Synodicon Orientale p. 261). The twelfth canon of the synod binds all bishops to obey whoever holds his see (Synodicon Orientale canon 12, p. 266). See the Church of the East Organises at Seleucia-Ctesiphon.