The Nicene Age · AD 313–400 · External witness
Yazdegerd I
king of kings of Persia AD 399 – 420 · Sasanian shah · Licenser of the Persian church · Seleucia-Ctesiphon
External witness
Who Yazdegerd I was
The Sasanian king who let the Persian church organise itself, twenty years after the persecution of Shapur II had ended and a century after it began.
He received **Marutha of Maypherqat** as a Roman envoy, was won over — the Syriac tradition credits Marutha's medical skill — and in 410 gave leave for a synod at **Seleucia-Ctesiphon** that received the Nicene creed, adopted twenty-one canons and made the bishop of his capital head of the church in his empire. **An edict of toleration is reported with it**: Christians to worship openly, ruined churches to be rebuilt, bishops to move freely in their dioceses.
**The archive holds the acts of that synod and states plainly what the king's part was**: not conversion, but licence. The church of Persia was permitted to become a structure, and it did so under a Zoroastrian sovereign, on the model of the church of an empire he was at war with for most of his dynasty's history.
⚠ **His reputation splits by source, and the archive prints both.** The Syriac and Greek Christian sources remember a benefactor; **Persian and later Arabic tradition calls him *bazahkar*, "the sinner"** — a verdict from the Zoroastrian nobility whose interests his tolerance crossed. ⚠ And the tolerance did not hold: it broke down in 419–420, on reports of Christians attacking fire-temples, and persecution resumed under his successor.
Also listed in non-christian witnesses.
Common questions
When did Yazdegerd I live?
Yazdegerd I is dated king of kings of Persia AD 399 – 420 in the archive, which places Yazdegerd I in the Nicene Age (AD 313–400).
Which early sources mention Yazdegerd I?
Yazdegerd I is named in 2 primary-source passages catalogued here, drawn from The Persian church and Socrates Scholasticus. Every passage is quoted from a named public-domain translation, earliest first.
Where was Yazdegerd I from?
The archive associates Yazdegerd I with Seleucia-Ctesiphon.
Who were Yazdegerd I’s contemporaries?
The archive links Yazdegerd I to 3 other figures, including Marutha of Maypherqat, Isaac of Seleucia and Shapur II. Each connection is drawn from a source that places them together, not from inference.
Primary-source mentions (2)
Every passage below is quoted from a named public-domain translation, earliest first.
The Synodicon Orientale — the acts of the synod of 410
c. AD 410[The king appears in the acts as the authority that made the assembly lawful: **the synod meets by his leave, and the concessions attributed to him — open worship, the rebuilding of ruined churches, freedom of movement for bishops — are recorded there.** ⚠ What the acts do not supply is a Persian document: **the archive has the church's account of the edict and not the edict.**]The Persian church · Synodicon Orientale: the synod of Isaac (410) · source text
*The Synodicon Orientale* — held in this library. Syriac, ed. and tr. J.-B. Chabot (Paris, 1902), French, public domain. ⚠ The acts are the church's own record of a king's permission, and read accordingly.
Socrates Scholasticus, Ecclesiastical History VII.8
c. AD 439[Socrates knows the Roman side of it — **Marutha's embassies to the Persian king, and their success for the Christians there** — and reports the shah's favour toward him. ⚠ **He says nothing of the synod of 410**, which is the archive's standing note on this event: the empire that sent the envoy did not record what the envoy achieved.]Socrates Scholasticus · Ecclesiastical History VII.8 · source text
Socrates, *Ecclesiastical History* — held in this library. English: A. C. Zenos, NPNF 2nd ser. 2 (1890), public domain.
Connected in the archive
People
Named alongside Yazdegerd I in the sources
This figure is placed with Yazdegerd I by the record — in a council roll, a martyr-act, a letter or a history — without Yazdegerd I 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 Yazdegerd I.