Jason, in Greek mythology, son of Aeson. When Pelias usurped the throne of Iolcus and killed (or imprisoned) Aeson and most of his descendants, Jason was smuggled off to the centaur Chiron, who reared him secretly on Mt. Pelion. Later Pelias promised Jason his rightful kingdom if he would bring the Golden Fleece to Boeotia. Jason assembled Greece's bravest heroes and together they sailed in the Argo in quest of the fleece. On their journey the Argonauts were seduced by beautiful women, attacked by warriors, buffeted by storms, and challenged by monstrous creatures. Finally the blind prophet Phineus told them how to make their way safely to Colchis, where the Golden Fleece was kept. When they arrived there, King Aeëtes demanded that before Jason take the fleece he yoke together two fire-breathing bulls, plow the field of Ares, and sow it with dragon's teeth obtained from Cadmus. Aeëtes' daughter Medea fell in love with Jason and gave him magical protection that allowed him to complete the tasks. In return Jason swore an oath of fidelity and promised to take her with him to Greece. When Aeëtes still refused to relinquish the fleece, Medea revealed its hiding place and drugged the guardian dragon. The Argonauts then fled Colchis with the fleece, pursued by Aeëtes. But Medea killed and cut to pieces his son Absyrtus, scattering the parts of his body in the sea. Aeëtes stopped to retrieve them. In another version, Absyrtus led the pursuit and, when Medea tricked him into an ambush, was killed by Jason.
Jason and Medea stopped to be purified of the murder by Circe at Aeaea, and there they were married. When they returned to Iolcus they found that Pelias had continued his tyrannical rule. Medea persuaded Pelias that he could be rejuvenated by having pieces of his body boiled in a magical brew. She then convinced his daughters that they should perform the task of cutting up their father. Pelias was thus murdered by his innocent daughters. Jason seized the city, but he and Medea were expelled by Acastus, the son of Pelias.
They sailed on to Orchomenses in Boeotia, where they hung the fleece in a temple. Then they went to Corinth. There Medea had rights to the throne, and Jason reigned for many years. But he forgot his oath and tried to divorce Medea so that he could marry Creusa, daughter of King Creon. In revenge, Medea, by magic and trickery, burned to death both the father and daughter. Because Jason had broken his oath, the gods caused him to wander homeless for many years. As an old man he returned to Corinth, where, resting in the shadow of the Argo, he was killed when the prow toppled over on him. The story of Jason and Medea appears frequently in literature, most notably in Euripides