Polemon II was the second son and middle child of the Pontic Rulers Polemon Pythodoros and Pythodorida of Pontus. His eldest brother was Zenon, also known as Artaxias III, who was Roman Client King of Armenia and his youngest sister was Antonia Tryphaena, who was married to Cotys VIII, King of Thrace.
The Pontic royal family was of mixed Anatolian Greek and Roman origin. His paternal grandmother is unknown; however his paternal grandmother could have been named Tryphaena, while his paternal grandfather was Zenon, a prominent orator and aristocrat, who was an ally to Roman Triumvir Mark Antony. His maternal grandparents were Pythodoros of Tralles, a wealthy Greek and friend of Pompey, and Antonia. Polemon II was the namesake of his parents and his maternal grandparents.
Through his maternal grandmother he was a direct descendant of Mark Antony and his second wife Antonia Hybrida Minor. Antony and Antonia Hybrida were first paternal cousins. He was Antony’s second born great grandson and great grandchild. Polemon II is the only known male descendant of Mark Antony that carries his name. The other male descendant of Mark Antony who carries a form of his name Antonius was the consul Quintus Haterius Antoninus. Through Antony, his great maternal aunt was Queen Cleopatra Selene II of Mauretania. Through Antony, he was a distant cousin to Roman Client King Ptolemy of Mauretania and the princesses named Drusilla of Mauretania. Through Antony, he was also a distant cousin to Roman emperors Caligula, Claudius and Nero and Roman empresses Valeria Messalina, Agrippina the Younger and Claudia Octavia.
Polemon II’s father died in 8 BC. His mother then married King Archelaus of Cappadocia, and the family had moved to Cappadocia, where Polemon II was raised, along with his siblings, at the court of his stepfather. Archelaus died in 17, whereupon Polemon II and his mother moved back to Pontus. From 17 until 38, Polemon II lived as a private citizen in Pontus and assisted his mother in the administration of their realm. When his mother died in 38, Polemon II succeeded his mother as the sole ruler of Pontus, Colchis and Cilicia.
According to an honorary inscription at Cyzicus in 38, Polemon II participated in celebrating the local games in the city, honoring Julia Drusilla, the late sister of Caligula; in this way Polemon II expressed his loyalty to the emperor and the Roman state. Polemon II with another Roman Client King Antiochus IV of Commagene, held athletic games in honor of Claudius in Cilicia in 47. Antiochus IV with Polemon II had showed favor towards Claudius in which they offered significant services to him.
Around 50, Polemon II was attracted to the wealth and beauty of the Judean princess Julia Berenice, whom he had met in Tiberias during a visit to King Agrippa I. Berenice in turn wanted to marry Polemon II to end rumors that she and her brother were committing incest. Berenice was previously widowed in 48 when her second husband, her paternal uncle Herod of Chalcis, died. She had two sons by him, Berenicianus and Hyrcanus. Berenice however set the condition that Polemon II had to convert to Judaism, which included undergoing the rite of circumcision, before marriage. Polemon II assented, and the marriage went ahead. It did not last long however, and Berenice left Pontus with her sons and returned to the court of her brother. Polemon II abandoned Judaism and, according to the legend of Bartholomew the Apostle, he accepted Christianity, but only to become a pagan again.
At an unknown date perhaps after the early 50s, Polemon II married a princess called Julia Mamaea who was from the Syrian Roman Client Emesene Kingdom. Mamaea was of Assyrian, Armenian, Greek and Median ancestry. Polemon II married Mamaea as his second wife and the circumstances that lead Polemon II to marry her are unknown. Through Mamaea’s marriage to him, she became a Roman Client Queen of Pontus, Colchis and Cilicia.
The relationship between Polemon II and Mamaea is unknown. Mamaea marrying Polemon II is only known through surviving evidence. Her name and identity is revealed from surviving bronze coinage. Surviving coinage that was issued from Polemon II and Mamaea is extremely rare, as only three specimens are known. On surviving coinage, shows her royal title in Greek ΙΟΥΛΙΑΣ ΜΑΜΑΙΑΣ ΒΑΣΙΛΙΣΣΗΣ (of Julia Mamaea the Queen) or ΒΑΣΙΛΙΣΣΗΣ ΙΟΥΛΙΑΣ ΜΑΜΑΙΑΣ (of Queen Julia Mamaea). These coins can be dated from the second half of Polemon II’s reign from 60 until 74. She bore Polemon II two sons who were Polemon and Rhoemetalces. Her sons that she bore to Polemon II are known from a restored surviving inscription from Amphipolis Greece, that is commemorating Polemon II, Polemon and Rhoemetalces is dated from the second half of the 1st century.
Polemon II renamed the town Fanizan and named the town after himself to Polemonium (modern Fatsa Turkey). In 62, Nero induced Polemon II to abdicate the Pontian throne, and Pontus, including Colchis, became a Roman province. From then until his death, Polemon II only ruled Cilicia.