The Nicene Age · AD 313–400
Isaac of Seleucia
catholicos c. AD 399 – 410 (held at the timeline’s ceiling) · Catholicos of Seleucia-Ctesiphon · Seleucia-Ctesiphon (Sasanian Persia)
The Nicene Age
Who Isaac of Seleucia was
Primate of the Church of the East at the turn of the fifth century, and the man who brought the Persian church out of persecution and into order. With Marutha of Maypherqat he convened the synod of 410 at Seleucia-Ctesiphon — the first council in the Sasanian empire held with the king’s permission — which accepted the Nicene creed and canons and organised the Persian sees under his own. His acts open the Synodicon Orientale. Distinct from Isaac of Dalmatia, and from the martyr-bishop Isaak in Sozomen’s roll.
Named once in the sources within the horizon; no other ancient witness names him.
Common questions
When did Isaac live?
Isaac of Seleucia is dated catholicos c. AD 399 – 410 (held at the timeline’s ceiling) in the archive, which places Isaac in the Nicene Age (AD 313–400). The dating is traditional and approximate; the archive marks it as uncertain rather than fixing a year the sources do not give.
Which early sources mention Isaac?
Isaac of Seleucia is named in 1 primary-source passage catalogued here, drawn from Synodicon Orientale. Every passage is quoted from a named public-domain translation, earliest first.
Where was Isaac from?
The archive associates Isaac of Seleucia with Seleucia-Ctesiphon (Sasanian Persia).
Who were Isaac’s contemporaries?
The archive links Isaac of Seleucia to 3 other figures, including Marutha of Maypherqat, Papa bar Aggai and Yazdegerd I. Each connection is drawn from a source that places them together, not from inference.
Primary-source mentions (1)
Every passage below is quoted from a named public-domain translation, earliest first.
Synodicon Orientale — the acts of the Synod of Mar Isaac (410)
c. AD 410[The canons of Nicaea received in Persia under Isaac, catholicos of Seleucia-Ctesiphon.]Synodicon Orientale · Synodicon Orientale, Synod of Mar Isaac (410) · source text
Connected in the archive
People
Named alongside Isaac in the sources
This figure is placed with Isaac by the record — in a council roll, a martyr-act, a letter or a history — without Isaac naming them in return.
Events in this lifetime
- AD 339 · The persecution of Shapur II, AD 339
- AD 343 · The Council of Serdica, AD 343
- AD 361 · Julian’s pagan restoration, AD 361
- AD 366 · Damasus and the catacomb epigrams, AD 366
- AD 367 · Athanasius lists the 27 NT books, AD 367
- AD 372 · The martyrdom of Sabbas the Goth, AD 372
- AD 378 · Queen Mavia’s revolt, AD 378
- AD 380 · The Edict of Thessalonica, AD 380
- AD 381 · The Council of Constantinople, AD 381
- AD 381 · The Council of Aquileia, AD 381
- AD 384 · The Altar of Victory petition, AD 384
- AD 390 · Thessalonica and the penance of Theodosius, AD 390
- AD 397 · Carthage confirms the canon, AD 397
Place
Places served
The one place the sources put Isaac.