Only Greco-Bactrian coinage is minted in such a realistic detail. Greek engravers were hired to carve coin dies used in the minting process. Pontic ruling dynasty was very proud of its Iranian descent, and the portraits clearly show their oriental features. Mithridates III struck a coin with a Zeus holding an eagle on one side, and the other side portrayed himself as a non-idealized bearded old man with a short hair. It was customary to have more realistic coin portraits in the east. However, the Pontic dynasty had married early in the Seleucid royal line. The Pontic Kingdom remained stubbornly resistant to foreign influence. Despite the ruling dynasty's Iranian origins, the Pontic state is considered to be a Hellenistic state. Most of the population was also ethnically Iranian. Pontic portraiture developed outside the typical Hellenistic art. Mithridates V was the first king who had a relatively idealized portraiture about himself in coinage. The trend was further developed by his son Mithridates VI. The trend may have started from wishes of Mithridates V to show his Greek side more than his oriental background. Late Hellenistic Pontic coinage have been found around the Mediterranean. This may indicate mobility of people and goods from the period contemporary with the Pontic kingdom. Pontic coinage has been found from same coin hoards together with other Hellenistic coinage. Such hoards have been found from the Near East and in south-eastern Anatolia. It is likely that Pontic coins were widely accepted in the eastern Mediterranean region. The Kingdom of Bosporus was governed after its conquest by a son of Mithridates VI. Pontic coinage has been found from northern shores of the Black Sea. It has been suggested that Mithridates VI's policy allowed more isolated cities of the kingdom from central Black Sea region to profit. His goal may have been to bring a sense of unity to these cities. He allowed the most important cities to have their own copper coinage. Amaseia became exceptionally, for a brief period of time, the only Pontic city allowed to strike its own silver and gold coinage. Mithridates VI allowed this as a reward for the city's service for him. He also encouraged mints managed by temples. Mithridates VI imitated Alexander the Great in coin portraits. His coin portraits portray him as a young man with a flowing hair, long sideburns, a prominent nose and a narrow forehead.