Aeson
Αἴσων
Jason's father, robbed of his throne — made young again by Medea's magic.
He was the rightful king of Iolcus, but his half-brother Pelias seized the throne, and he sent his son Jason to be raised in hiding by the centaur Chiron.
The quest for the Golden Fleece itself was an errand Pelias invented to be rid of Jason.
In Ovid, Medea returns and exchanges his blood for a magic brew, restoring his youth. It is nearly the only scene where Medea's magic is used for good.
SourcesOvid, Metamorphoses