In the year 172 BC or 171 BC, thanks to the diplomatic efforts of her maternal half-brother Seleucid King Demetrius I Soter, Nysa married the King Pharnaces I of Pontus.
[1][5] The marriage between Pharnaces and Nysa represented a continuation and a strengthening of the pro-Seleucid orientation of Pontus' foreign policy.
Pharnaces set about establishing good relations with the citizens of Athens and the Greek island of Delos.
[6] A lengthy inscription from the Athenians on Delos honours Pharnaces and Nysa.
Pharnaces and Nysa received a crown of gold from them and bronze statues of themselves were set up on Delos.