In Greek mythology, the Pallantidai (Παλλαντίδαι) were the fifty children of Pallas, nobles of Attica. They fought against their cousin, Theseus because they would not accept him as king. Leos, a herald of Theseus, warned him of their schemes and an ambush they had prepared for him. Theseus pre-emptively ambushed the Pallantides and killed all but the girl, Aricia, whom, some traditions say, Theseus kept as slave.
Some scholars believe that the east frieze of the Hephaisteion depicts this battle.