Jason, grandson of the god Poseidon (Neptune), led the expedition of the Argonauts in quest of the golden fleece. He first married Medea (q.v.), but afterwards repudiated her for Glauke, daughter of Kreon, King of Corinth. - His. first wife took a terrible revenge, which is the subject of the Medea of Euripides (q.v.). The story of the fleece is supposed to be an Ionian sun-myth.