Pontus, in ancient times, was the name of the northeastern province of Asia Minor, a long and narrow strip of land on the southern coast of the Black Sea (Pontus Euxinus), from which the designation was later transferred to the country. Before this the province was called Cappadocia on the Pontus. The country was shut in by high and wild mountain ranges, but was exceedingly fertile in the lower parts on the coast, in the interior, and on the plateaux. It yielded fruit of all kinds, especially cherries, which Lucullus is said to have brought into Europe from Pontus 72 B.C.; also wine, grain, wood, honey, wax, etc., besides iron, steel, and salt. It was inhabited by a number of petty tribes; among these were the Chalybes or Chaldans, held in high repute by the Greeks as the first smiths. All belonged to the Persian empire, but in Xenophon’s day (about 400 B.C.) were to a considerable degree independent of the Persians. At this date, however, these different countries had no common name. Greeks settled early on the coast, and founded flourishing commercial cities, as Trapezus (Trebizond), Cerasus, Side, later called Polemonium, Cotyora, Amisus, and Apsarus. The founder of the Kingdom of Pontus was Mithradates I, son of Prince Mithradates of Cius on the Propontis, who was murdered 302 B.C. Mithradates I, taking advantage of the confusion caused by the Diadochian Wars, came to Pontus with only six horsemen and was able to assume the title of king 296 B.C.; he died in 266 after a reign of thirty-six years. He was followed by Ariobarzanes (d. about 258 B.C.), Mithradates II (to about 210 B.C.), Mithradates III (to about 190 B.C.), Pharnaces (to 170 B.C.), Mithradates IV (to about 150 B.C.), Mithradates V (to 121 B.C.), and then Mithradates VI Eupator, or the Great. The kings, Persian by descent, formed relations early with Greece and from the beginning Hellenistic culture found an entrance into Pontus. The religion was a mixture of Greek worships with the old native cults. From the time of Pharnaces the kings were allied with the Romans. Mithradates VI became involved in three wars with the Romans (88-84, 83-81, 74-64), and finally his kingdom, which he had increased by the conquest of Colchis, the Crimea, Paphlagonia, and Cappadocia, was lost to the Romans (63). The territory west of the River Halys, the coast of Paphlagonia, and the valley of the Amnias became a part of Roman territory and with Bithynia were united into the double Province of Bithynia and Pontus. The other parts were made into principalities and free cities, and it was not until 7 B.C., A D. 18, and A.D. 63 that they were gradually absorbed by Rome. Under Diocletian (284-305) Pontus became a diocese of the empire. The Pontus mentioned in the Old Testament of the Vulgate in Gen., xiv, 1, 9, is a mistaken translation, according to Symmachus, for the district of Ellasar (Larsa in southern Babylonia).
In Apostolic times Christianity found an entrance into Pontus. The First Epistle of Peter is addressed to the Christians in Pontus among others, showing that Christianity had spread to some extent in this province. The author in his exhortations presupposes relations between the faithful and the non-Christian population. For the years 111-13 we have the important testimony of Pliny, then Governor of Bithynia and Pontus (Ep. xcvi). Pliny did not mention the cities or villages, and it is uncertain whether Amastris, or Amasia, or Comana, was the place where Christians were tried by him. As concerns Amisus, Ramsay has proved from Christian sources that it contained Christians about the year 100. Later Amastris was the chief Christian community. Eusebius mentions (IV, xxiii) a letter written by Bishop Dionysius of Corinth (about 170) to Amastris, “and the other churches in Pontus”. There was, therefore, at this era a metropolitan with several churches. About 240 Gregory Thaumaturgus was consecrated Bishop of Neo-Cisarea by Phaedimus, Bishop of Amasia. It is said that at that time there were only seventeen Christians in the city and its vicinity, and that at his death, shortly before 270, only the same number of heathens could be found in the city. The able bishop converted the people by opposing Christian to heathen miracles and by changing the old feasts into Christian festivals. In the Decian persecution he made concessions to human weakness, advised the faithful to be less aggressive, and fled himself. Comana received a bishop from Gregory. Christianity obtained a foothold also in the Greek cities of the coast of eastern Pontus before 325. In or about the year 315 a great synod was held at Neo-Caesarea by Bishop Longinus. At the Council of Nicaea there were present among others the Bishops of Amastris, Pompejopolis, Jonopolis, Amasia, Comana, Zela, Trebizond, and Pityus. Towards the end of the fourth century Neo-Caesarea became itself a Church-province, having as suffragans Trebizond, Cerasus, Polemonium, Comana, Rhizum, and Pityus.