Synod of 424 and Church of the East autonomy
About this date: 424 is a jurisdictional marker, not the founding of the Church of the East or a church created by Nestorius in 431. The surviving account of an explicit declaration of autonomy has been questioned, and the broader separation was a process shaped by political and theological factors.
The synod under Catholicos Dādīšōʿ barred appeals to churches west of the Sasanian realm, consolidating the Persian church's self-government. This preceded the Council of Ephesus in 431; reception of Antiochene Christology and the loss of communion with churches of the Roman Empire developed later in the fifth century.
Perspective note
Shared subject; this bundled record was originally written with an Orthodox-informed editorial lens.