He is commemorated as a saint by the Syriac Orthodox Church in the Martyrology of Rabban Sliba, and his feast day is 22 April.
Whilst he had some success in dealing with the tritheists, Peter quarrelled with his erstwhile ally the Egyptian non-Chalcedonian Pope Damian of Alexandria, and entered into a schism with him that would persist past his death until 616.
[10] The earliest date 570/571 is disregarded as an erroneous copy of 581, and 578, although previously accepted by earlier Syriac historians, including William Wright, Rubens Duval, Carl Anton Baumstark, Jean-Baptiste Chabot, and Ortiz de Urbina, has since been rejected in favour of 581.
[10][13] John of Ephesus reported that Peter was consecrated patriarch of Antioch by Damian at Alexandria,[12] and is supported by the Chronicle of 1234,[10] whereas the historians Michael the Syrian and Bar Hebraeus record that Peter was consecrated at the aforementioned monastery of Saint Ananias by the archbishop Joseph of Amid with the support of the Egyptian non-Chalcedonians.
[20] After several years, the tritheists Elias and Theodore met with Peter on behalf of Conon of Tarsus and Antoninus to again discuss the patriarch's demands for their reunion.
[21] At the meeting's conclusion, Elias and Theodore accepted Peter's main conditions, and it was agreed they would write to the other tritheists at Constantinople to consult them before a union was formalised.
[22] A few days later, Peter received the delegation's reply and a letter from Elias declaring an end to talks of union as Conon and Antoninus refused to condemn proponents of tritheism.
[21] Elias underwent penance for a short period of time, presented Peter with a plerophoria (confession of faith) in accordance with his conditions on 21 July 585, and entered into communion with him.
[18] In c. 586, the formerly cordial relationship between Peter and Damian was soured by theological controversy, and ultimately led to schism between their two churches that would endure until its resolution in 616.
[26] Peter issued a letter addressed to the Church of Alexandria to encourage its members to prevail upon Damian to resolve the dispute.
[29] Thus the phylarch Jafna presided over two ill-fated meetings in Arabia in 587,[30] the first of which was held at a monastery, and the second took place at the Church of Saint Sergius at Jabiyah.