Jason (/ˈdʒeɪsən/; Greek: ἸάσωνIásōn) was an ancient Greek mythological hero who was famous for his role as the leader of the Argonauts and their quest for the Golden Fleece. He was the son of Aeson, the rightful king of Iolcos. He was married to the sorceress Medea. The oldest known texts mentioning Jason date to around 300 BC.