Peter was born at Al-Raqqa (Callinicus). His father Paul was a believing and truthful orator. Peter was raised in the best fashion, mastering Greek and Syriac and obtaining a fair knowledge of philosophy and theology. Because of his erudition and excellent character, he was chosen a patriarch of Antioch and was consecrated at the Monastery of Mar Hanania (Dayr ul-Zafaran) in the year 581. Then he traveled to Alexandria and the Arab province of Hawran to promote the religious ties be­tween the two Sees of Antioch and Alexandria.

He became popular for his dialogue with Damianus the Syrian, patriarch of Alexandria, who was confused in the exposition of the doctrine of the Trinity while attempting to refute the heresy of Tritheism, not because of adherence to heresy, but because of his shortsightedness in knowledge. When he refused to obey the counsel of Peter and attempted, obstinately, to evade discussion or defense of the matter, Peter refuted him in a book which he wrote in Greek, comprising four treatises in one hundred chapters and supported with testimonies from the authorities of the church. According to Mar Michael the Great this book contained three treatises only. Judging from the Syriac MS. preserved in London which comprises twenty-five chapters, i.e., the second book (second treatise), it is most likely that the book was abridged in fifty chapters by some of the writers who lived soon after his time. A copy of this book at the Vatican contains the second volume or the last book in fifty chapters covering four hundred pages.284 Peter also wrote a short treatise against the Tritheists, which is perhaps a part of his above mentioned lengthy book, and a treatise against the doctrine of the abbot John of Barbour as well as against Probus, in which he established that the difference of the definition be­tween the two natures of Christ after the unity is main­tained. He also wrote letters, of which two were abridged and incorporated by Michael the Great in his Chronicle, and a liturgy beginning thus, "0 God the Father and the eternal Almighty. " He died at the Outer Monastery of Gubba Baroyo (ܓܘܒܐ ܒܰܪܳܝܐ) on the 22nd of April, 591.