Region of Asia Minor that at its greatest extension spread from the Hellespont on the Propontis Sea of Marmara to the SE extremity of the Pontus Euxinus Black Sea, also including Honorias and Paphlagonia. Bithynia Pontus was the name of the province established in 65 64 BC, after the Roman conquest Tacitus, Annals I, 74. The witnesses to the apostolic glossolalia on the day of Pentecost included inhabitants of Pontus; Aquila was also from there Acts 2:9; 18:2. The rapid expansion of Christianity in that region is attested by 1 Pet, addressed to the exiles = Christians of the diaspora in Pontus and Bithynia. 1 Pet alludes to a state of persecution not unlike that referred to by Pliny the Younger, governor of the province in 112 Ep. 96, in his letter to Trajan; the letter is certainly later than Nero, perhaps datable to 80 95 DBS, VII, 1444-1453.
In Pontus, the progress of the gospel is attested by the work of Gregory Thaumaturgus. In Bithynia, the era of the martyrs culminated in the massacre of Nicomedia, the imperial residence from the time of Diocletian, which occasioned Lactantius’s conversion. The first ecumenical council 325 and the last of the patristic era 787 met at Nicaea, rival of Nicomedia where Constantine was baptized as capital of Bithynia. The first phase of Arianism brought the episcopate of Bithynia into prominence due to Eusebius of Nicomedia. Chalcedon was the seat of the fourth ecumenical council 451, which confirmed Nicomedia’s precedence and, in can. 28, extended the jurisdiction of the patriarchate of Constantinople to Pontus, a region made illustrious by the Cappadocians and from which Evagrius of Pontus took his name.