Medea

When Iason came to her father asking for the golden fleece (which would give him the royal crown), the king feared that he would be deprived of his rule, so he decided to give Iason an impossible task. It was: "To harness the fiery bulls to an iron plough, plough with them the field of the god of war, Ares, and sow it with the dragon's teeth from the serpent of Ares. Moreover, when the teeth grow into warriors, he must slay them all."

Hera, Iason's protector, decided to help by persuading Eros, the god of love, to strike the heart of Medea with his arrow of love. When the hero came to her asking for help, she fell in love with him and advised him to throw a stone among the dragon warriors for them to fight each other over. Then he can gradually defeat them. She also gave him a magic ointment (or mixture of herbs) that would make him invulnerable and invincible for a day. When, thanks to this help, Iason accomplished the task and again asked the king for the golden fleece, he was again refused. Medea therefore led him to the grove with the golden fleece and put the dragon to sleep. Then they fled together to Argo and sailed away.

After three days, King Aeetes' fleet under the command of Medea's brother Apsyrtus caught up with them. Medea lured her brother to a deserted place, where Iason murdered him and threw his dismembered body into the river, delaying the entire fleet, and they managed to escape. Shortly afterwards, Iason married Medea.

Returning home, they went to Pelius to take over the government. However, he refused them, so Iason decided to kill him, again with the help of Medea. She restored his father Aison to youth, and when the daughters of Pelius asked for the same spell, she promised them that she would do so, with the proviso that they must cut their father's throat. As it was, Medea let him bleed to death. This angered Acastus, the son of Pelius, from whom the couple had to flee and give up thoughts of gaining the throne.

After years on the run, they found refuge with the Corinthian king Creonte, and here their two sons Mermeros and Pherethês were born. Iason, however, still wanted to win the royal crown, so he decided to marry Creonte's daughter Glaucia. He told Medea that he wanted to ensure his sons' future by doing this. This angered her so much that she killed Creontes, Glauca, and both of her sons. She did this so that Iason would be tormented by grief until his death. Medea then disappeared somewhere in the east, supposedly in the land beyond the Tigris, which was named Medea after her.