Helen of Troy refuge with Leda. The swan gained her affection, and the two mated. Leda then produced an egg, from which Helen emerged. The First Vatican Mythographer introduces the notion that two eggs came from the union: one containing Castor and Pollux; one with Helen and Clytemnestra. Nevertheless, the same author earlier states that Helen, Castor and Pollux were produced from a single egg. Pseudo-Apollodorus states that Leda had intercourse with both Zeus and Tyndareus the night she conceived Helen. On the other hand, in the "Cypria", part of the Epic Cycle, Helen was the daughter of Zeus and the goddess Nemesis.
Leda and the Swan Leda and the Swan Leda and the Swan is a story and subject in art from Greek mythology in which the god Zeus, in the form of a swan, seduces the mortal woman Leda. According to later Greek mythology, Leda bore Helen and Polydeuces, children of Zeus, while at the same time bearing Castor and Clytemnestra, children of her husband Tyndareus, the King of Sparta. In the W. B. Yeats version, it is subtly suggested that Clytemnestra, although being the daughter of Tyndareus, has somehow been traumatized by what the swan has done to her mother (see below). According to