In Greek mythology, Neoptolemus, originally called Pyrrhus at birth, was the son of the mythical warrior Achilles and the princess Deidamia, and the brother of Oneiros. He became the progenitor of the ruling dynasty of the Molossians of ancient Epirus. In a reference to his pedigree, Neoptolemus was sometimes called Achillides or, from his grandfather's or great-grandfather's names, Pelides or Aeacides. According to Pseudo-Apollodorus, he is the ancestor of Olympias, mother to Alexander the Great. According to Plutarch, Neoptolemus was also the ancestor of Pyrrhus of Epirus.