Mnemosyne — Classical Greek Myth Library

Leda, wife of Tyndareus king of Sparta, was loved by Zeus, who approached her in the form of a swan. On the same night (in the common handbook reconciliation of traditions) Tyndareus also lay with her. From this double union came children of mixed or disputed paternity, often born from eggs. Classical accounts vary on who hatched from which egg and who was mortal or divine. A widespread scheme holds that Zeus fathered Polydeuces (Pollux) and Helen, while Tyndareus fathered Castor and Clytemnestra—or that both Dioscuri were Zeus’s, or that Helen alone was the swan’s child. Euripides and others speak of Helen produced from an egg; vase-painting and later mythography show Leda with the egg or Nemesis as the true mother of Helen in an alternate strand (Zeus pursues Nemesis as swan; the egg is given to Leda to hatch). Castor and Polydeuces—the Dioscuri—became the divine twins of Sparta: horsemen, boxers, saviors of sailors. When Castor was killed, Polydeuces shared his immortality so that the brothers alternated between Olympus and the underworld (Pindar, Apollodorus). Helen, Zeus’s daughter, grew to be the most beautiful of women; her wooing, the oath of Tyndareus, and her abduction by Paris open the Trojan cycle. Clytemnestra married Agamemnon. This entry covers the Spartan birth complex; Helen’s eidolon (Stesichorus / Euripides) is catalogued separately under the Trojan cycle.