Jason was an ancient Greek mythological hero, son of Aeson of Iolcus and leader of the Argonauts on the quest for the Golden Fleece. Aided by the Colchian sorceress Medea, whom he married, he retrieved the fleece from King Aeëtes but later abandoned Medea in Corinth, bringing ruin on their house. He appears in Apollonius of Rhodes's Argonautica, Euripides's Medea, and many later adaptations.
Adapted from Wikipedia, "Jason" · CC BY-SA 4.0
I.Persecution by Pelias
Jason's father Aeson was the rightful king of Iolcus; his half-brother Pelias seized the throne and killed Aeson's other descendants. Aeson's wife (often Alcimede) hid the infant Jason and sent him to be reared by Chiron. An oracle warned Pelias to beware a man with one sandal. Years later Jason, returning to Iolcus, lost a sandal helping an old woman — Hera in disguise — across the river Anauros. Pelias set him the remote task of fetching the Golden Fleece as the price of the throne.
II.The Argonauts and the Fleece
Jason assembled heroes aboard the Argo — among them Heracles, Orpheus, the Dioscuri, the Boreads, Peleus, Meleager, and Atalanta in some lists. Their voyage included Lemnos, the tragic battle with the Doliones, Phineus and the Harpies, and the passage of the Symplegades. In Colchis Aeëtes demanded that Jason yoke fire-breathing bulls, sow dragon's teeth, and overcome the fleece's guardian dragon. Medea, made to love Jason by divine design, supplied charms and counsel; they fled with the fleece, and Absyrtus was killed to slow pursuit.
On the return the Argonauts faced Sirens (defeated by Orpheus), Talos on Crete, and purification with Circe. At Iolcus Medea engineered Pelias's death through his daughters; Acastus then drove Jason and Medea into exile at Corinth.
III.Corinth and death
In Corinth Jason sought a new marriage alliance with Creon's daughter Glauce (Creusa). Medea's revenge — the poisoned gifts that killed bride and king, and the murder of their children — is told most influentially by Euripides. Jason later reclaimed Iolcus with Peleus's help in some accounts; having broken his vow to Medea, he lost Hera's favor. Tradition holds that he died when the rotting prow of the Argo fell on him as he slept beneath it.
Jason's parentage on his mother's side varies widely across authors (Alcimede, Polymede, Amphinome, and others), but Aeson remains constantly his father.