View source for Isaac of Seleucia-Ctesiphon

ISAAC, Bishop of Seleucia-Ctesiphon and Catholicos of the Church of the East (399-410; see CHRISTIANITY i, ii, iii). Isaac is said to have come from Kashgar and to have been a relative of an earlier bishop of Seleucia-Ctesiphon, Tomarsa (363-371). He was elected to office (after an interregnum caused by earlier persecution) in 399 at the time when [[Marutha of Maiperkat|Marutha, bishop of Maipharqat]], had been sent by the Roman emperor Arcadius on embassy to Yazdegerd I at his winter residence in Seleucia-Ctesiphon. On this visit [[Marutha of Maiperkat|Marutha]] won the shah's favour as a result of his medical skill; thank to this, [[Marutha of Maiperkat|Marutha]]'s second embassy to Yazdegerd I in 410 provided the opportunity to get royal permission to summon a synod of 40 bishops, to strengthen Isaac's position against some bishops who were causing him trouble, and to regularize church affairs in general. At this synod [[Marutha of Maiperkat|Marutha]] read out a letter from the "western bishops" (that is, from the Eastern Roman Empire) and the doctrinal creed of the Council of Nicaea (325) was formally accepted by the Church of the East, along with the decrees of various provincial church synods of the Eastern Roman Empire. Internal church affairs were also regulated in a series of 21 canons.The texts of the Creed and of the canons survive in both an East and a West Syriac recension, and it is the latter which has preserved the original text of the form of the Nicaean Creed accepted at the synod.

The most detailed (but clearly, edited) account of this important synod of 410 is found in the East Syriac collection of synods known as the Synodicon Orientale. Shorter, but sometimes also embroidered, accounts are to be found notably in the Chronicle of Seert (sec. 66), Barhebraeus' Ecclesiastical History (II. 16), and the East Syriac writers Mari and Sliba. It should be noted that, although the embassies of [[Marutha of Maiperkat|Marutha]] are mentioned both in Socrates, Ecclesiastical History (VII. 8) and in the Armenian and Greek Lives of [[Marutha of Maiperkat|Marutha]], no reference is made in any of these sources either to the synod of 410 or to Isaac.

=== Bibliography ===

* Jean Baptiste Chabot, Synodicon Orientale, ou receuil des synodes nestoriens, Paris, 1902, pp. 253-75, 292-93. 
* Jean Dauvillier, "Droit (chalde‚en)," in Dictionnaire de droit canonique 3, 1942, cols. 292-388, esp. 301-304. 
* Andre‚ de Halleux, "Le symbole des e‚vêques perses au synode de Se‚leucie-Ctesiphon (410)," in Gernot Wiessner, ed., Erkenntnisse und Meinungen, II = Göttinger Orientforschungen, Reihe Syriaca 17, 1978, pp. 161-90. 
* Jean Maurice Fiey, "Isaac (catholicos)," in Dictionnaire d'histoire et de ge‚ographie eccle‚siastique 26, 1997, pp. 90-92. 
* Jean Gribomont, "Le symbole de la foi de Se‚leucie-Ctesiphon (410)," in Robert H. Fischer, ed., A Tribute to Arthur Vööbus: Studies in Early Christian Literature and its Environment, Chicago, 1977, pp. 283-94. 
* Jerome Labourt, Christianisme dans l'empire perse sous la dynastie sassanide (224-632), Paris, 1904, pp. 87-99. 
* Thomas Joseph Lamy, Concilium Seleuciae et Ctesiphonti habitum anno 410, Leuven, 1868. 
* Ralph Marcus, "The Armenian Life of Marutha of Maipharkat," Harvard Theological Review 25, 1932, pp. 47-71. 
* Jacques Noret, "La vie grecque ancienne de s. Maruta de Mayferqat," Analecta Bollandiana 91, 1973, pp. 77-103. 
* Arthur Vööbus, "New Sources for the symbol in early Syrian Christianity," Vigiliae Christianae 26, 1972, pp. 291-96 (West Syriac recension of Creed of 410). 

(SEBASTIAN BROCK)

20 August 2003

=== Links ===

[[http://www.iranica.com/articles/supp4/Isaac.html Encyclopedia Iranica]] article by Sebastian Brock.