Jason was a Thessalian hero, also known as Iason. His father was, Aeson, son of Cretheus and Tyro (the latter was the object of Poseidon's affections). Aeson was robbed of his kingdom, the land of Iolcus, by his half brother Pelias, son of Tyro and Poseidon. Aeson gave Jason to the centaur Chiron to raise. When he reached maturity Jason returned to Pelias wearing only a panther-skin to claim his right to the kingdom. In the middle of sacrifice Pelias could not outright refuse the young man, but he was scared; an oracle had warned him "to beware of the man that had no shoe." Instead Pelias asked Jason to bring him back the Golden Fleece from the ram, which in earlier days Phrixus and Helle of Greece had taken to Colchis. The journey and mission would be dangerous, because the ram, it was known, was kept in a woods sacred to Ares, and guarded by a most fearsome dragon place their by the king Aeites, son of the sun, and a sea-nymph, Perseis. Pelias believed Jason would never return.
After accepting the mission Jason sought the advice of Argos, son of Phrixus. With the prompting of Athena Argos built the Argo, the first longship capable of taking Jason and his companions to Colchis situated on the far shore of the Black Sea. The major portion of the ship was made of wood from Mount Pelian, but the prow was made of a piece of oak from Dodona, where Zeus had an oracle; Athena provided it, and this wood was endowed with the powers of speech and prophecy.
The crew was assembled and the journey started well, for the omens were good. The first landfall was Lemnos, where only women lived because they had killed their unfaithful husbands whom Aphrodite had put a curse on. These women were kind to the sailors, and bore them sons, founders of a new race. At Samothrace, the Argonauts were initiated into the mysteries of Cabeiri, which were celebrated on the island.
Jason was the Greek legendary hero and leader of the Argonauts, who sailed to Colchis in the ship Argo to capture the Golden Fleece. Jason crossed a sea of marvels, accomplished difficult tasks, circumvented the guardian dragon, and returned powerful with the fleece. Partly his success was due to the magic of a Colchian princess, Medea, whom he promised to marry, with the assistance of the goddess Athena. Medea seemed to have been associated with dismemberment. When the Argo hastened away with its prize, she suggested that they cut up her brother Apsyrtus and throw the parts of his body overboard to slow down the swift pursuit of her father, King Aietes. The Argonauts did so, forcing the Colchians to collect the remains for a decent burial. Upon the return of the heroes to Greece, Medea persuaded the daughters of King Pelias of Iolcus to cut their father into pieces and boil him, so as to restore him to youth. They did so, with the expected consequence, and thereby avenged the death of Jason's own father.
After some years Jason deserted Medea to marry Glauce, but killing Glauce and their children revenged Medea. Jason himself is said to have died when a piece of the rotting Argo fell on his head. The many myths surrounding the hero are filled with diverse elements, Jason, his name, for instance, means "healer," and possibly suggests his origin was as a different figure. A.G.H.
Grimal, Pierre, Larousse World Mythology, Secaucus, New Jersey, Chartwell Books, 1965, pp. 149-152 Cotterell, Arthur, A Dictionary of World Mythology, New York, G. P. Putman's Sons, 1980, p. 145