In Greek mythology, Pontus ("sea") was an ancient sea-god, son of Gaia and Aether. With Gaia, he was the father of Nereus, Thaumas, Phorcys, Ceto and Eurybia. With Thalassa, he was the father of the Telchines.
Pontus was a name applied in ancient times to extensive tracts of country in the northeast of Asia Minor (modern Turkey) bordering on the Euxine (Black Sea), which was often called simply Pontos (the Main), by the Greeks. The exact signification of this purely territorial name varied greatly at different times. The Greeks used it loosely of various parts of the shores of the Euxine, and the term did not get a definite connotation till after the establishment of the kingdom founded beyond the Halys during the troubled period following the death of Alexander the Great, about 301 BC, by Mithradates I, Ktistes, son of a Persian satrap in the service of Antigonus, one of Alexander's successors, and ruled by a succession of kings, mostly bearing the same name, till 64 BC.
As the greater part of this kingdom lay within the immense region of Cappadocia, which in early ages extended from the borders of Cilicia to the Euxine, the kingdom as a whole was at first called "Cappadocia towards the Pontus", but afterwards simply "Pontus," the name Cappadocia being henceforth restricted to the southern half of the region previously included under that title. Under the last king, Mithradates Eupator, commonly called the Great, the realm of Pontus included not only Pontic Cappadocia but also the seaboard from the Bithynian frontier to Colchis, part of inland Paphlagonia, and Lesser Armenia. With the destruction of this kingdom by Pompey in 64 BC, the meaning of the name Pontus underwent a change. Part of the kingdom was now annexed to the Roman Empire, being united with Bithynia in a double province called "Pontus and Bithynia": this part included only the seaboard between Heracleia (Eregli) and Amisus (Samsun), the ora Pontica. Hereafter the simple name Pontus without qualification was regularly employed to denote the half of this dual province, especially by Romans and people speaking from the Roman point of view; it is so used almost always in the New Testament.
- Paphlagonia, to which was attached most of the old province Pontus
- Diospontus, re-named Helenopontus by Constantine, containing the rest of the province Pontus and the adjoining district, eight cities in all (including Sinope, Amisus and Zela) with Amasia as capital
- Pontus Polemoniacus, containing Comana, Polemonium, Cerasus and Trapezus with Neocaesarea as capital
- Armenia Minor, five cities, with Sebasteia, as capital.