Pylæmenes II/III Euergetes
Paphlagonia was in northern Anatolia and was bordered by Bythnia to the west, Pontus to the east, and Galatia to the south.
"In the Homeric catalogue we find Pylæmenes leading the Paphlagonians as allies of the Trojans; from this Pylæmenes the later princes of Paphlagonia claimed their descent, and the country was sometimes from them called Pylæmenia." -Pliny, Natural History, 6.2.2
"Him (son of Pylaemenes) the great-hearted Paphlagonians tended, and setting him in a chariot they bare him to sacred Ilios, sorrowing the while, and with them went his father, shedding tears; but there was no blood-price gotten for his dead son."
About a thousand years later, Mithridates VI Eupator made a deal with Nicomedes III of Bythnia to invade and split up Paphlagonia in 108/107 BC. There was a pretense as well that Pylaemenes had bequeathed his Kingdom to Mithridates V. Between 107 and 101 BC, Nicomedes then invaded Cappadocia only to be subsequently conquered by Mithridates VI, expanding his position as the dominant force in Asia minor and rival to Rome.
For more on Mithridates use of his family members (and disposal of his family members) to control Cappadocia, see my note on "A Father's Support". A few years later when Tigranes, king of Armenia, with support from Mithridates VI, chased the Roman installed king Ariobarzanes out of Cappadocia, Sulla was sent to restore him to power circa 94 BC.
Most of this had not yet transpired when this coin was minted, although the dates that I have for this coin do overlap a bit with the invasion of Paphlagonia which I cannot explain :
Kings of Paphlagonia, Pylaemenes II/III Euergetes (Circa 133-103 BC), AE20 4.98g Obv: Bust of Pylaemenes right, as Herakles, with club over shoulder and lion skin around neck Rev: ΒΑΣΙΛΕΩΣ / ΠΥΛΑΙΜΕΝΟΥ ΕΥΕΡΓΕΤΟΥ, Nike standing left, holding wreath and palm frond Ref: SNG BM Black Sea 1550; HGC 7, 440
Glew, D. (1987). The Cappadocian expedition of Nicomedes III Eurgeter, King of Bythnia. Museum Notes (American Numismatic Society), 32, 23-55.
Pliny, Natural History
Smith, William Ed. (1854), Dictionary of Greek and Roman geography, Paphlagonia