Molpadia was a participant in the Attic War, where she witnessed her queen Antiope sustain heavy injuries. Antiope was hurt so seriously that she could not defend herself from Theseus and his retainers. Knowing this, Molpadia killed the queen with an arrow or spear, saving her from violation by the Athenian king. According to other version, Molpadia killed Antiope by accident. She was afterwards killed by Theseus, and her tomb was shown at Athens.