Meleager & Atalanta

This myth is the story of Meleager, one of the heroes of the Argonautic expedition. When he was born, the Fates determined that his life should last no longer than a particular brand, and his mother immediatly seized it and carefully preserved it until his son was a man.

So Meleager grew up, and one day there was a fight. His father had omitted to pay his respects to Diana, and as a revenge she sent a huge boar after them. There was a huge battle, and his friend Atalanta finally killed the boar. Meleager rewarded her, but his mother's brothers stole the reward and as a punishment Meleager slayed them.

Her mother finds out, and she is furious. She decided to get rid of the brand, but her feelings conflict; "now she is pale at the thought of the proposed deed, now flushed again at the act of her son." In the end she kills her son.

I think it's interesting that the myth says that sisterly affection is stronger than motherly affection. Usually it's the child that trumps everything else, and a mother doesn't think twice about sacrificing everything for it.