Medea was the daughter of Aeëtes, king of Colchis, a land on the east coast of the Black Sea.  She was a priestess of Hecate and a sorceress.  She met and fell in love with Jason when he arrived in her land as the leader of the Argonauts.  His mission, imposed by Pelias, king of Iolcus, was to acquire the Golden Fleece and to bring it back to Pelias.  Medea helped Jason perform the tasks imposed on him by her father, Aeëtes, and then helped him to escape from Colchis.  Returning to Iolcus, Jason again had the assistance of Medea in removing Pelias.  There are several versions of the story.  In one of the better known, Medea persuaded the daughters of Pelias that he could be rejuvenated if they boiled him in a pot.  In this way, they unwittingly killed their father.  Jason might then have become king, as was his right, because his father had been king until he was banished by the wicked Pelias.  But the story takes Jason on to Corinth, where the action of Euripides' play is set.  Euripides' version of the murder of the children of Medea and Jason is not the only one.  According to other versions, Corinthian women killed the children and finally were obliged to establish a cult in their honor; or the relatives of Creon, king of Corinth, killed them; or Medea killed them accidentally.  Medea's later life in Athens and beyond is also variously told.