What is "phrygius"

For the river, see Hyllus, for the writer Dares Phrygius

Phrygius a Neleid, was king of Miletus after Phobius, who fell in love with Pieria daughter of Pythes from Myus, at a festival of Artemis. He promises anything, and Pieria asks for peace between the two cities, which were at war. In this way, the war between Miletus and Myus stopped.