In 421–22 P. was already at the Byzantine court. According to the accounts of his biographers, he was the son of King Bosmarius and had been sent to Constantinople as a hostage; but both these details are doubtful. He fled to Jerusalem, where he was received by St Melania (d. 439), who made him a monk (c. 430). There he founded a monastery near the Tower of David, later called the Iberian monastery. Persecuted as a steadfast Monophysite, he took refuge near Gaza, and after his priestly ordination (446) and consecration as bishop of Maiuma (453), he went to Egypt where he took part in the consecration of Timothy Aelurus (457). He returned to Palestine but, refusing to subscribe to the Henoticon (v.), he went into hiding in Phoenicia.
His influence among the Monophysites was immense, as is shown by the Pierfiorie of John Rufus (PO, 8).