List of patriarchs of the Church of the East

The Patriarch of the Church of the East was the head of the Church of the East. According to tradition, the Church of the East was founded by the apostles Thomas, Addai, Aggai, and Mari in the first century AD. At the end of the third century or beginning of the fourth century AD, Papa bar Aggai, as bishop of Seleucia-Ctesiphon, was recognised as the first supreme head of the Church of the East, according to the Chronicle of Arbela.

Source: Wikipedia — List of patriarchs of the Church of the East (CC BY-SA 4.0)