Clytemnestra produced four offspring from two eggs: Castor and Clytemnestra from one egg, and Helen and Polydeuces (Pollux) from the other. Therefore, Castor and Clytemnestra were fathered by Tyndareus, whereas Helen and Polydeuces were fathered by Zeus. Agamemnon and his brother Menelaus were in exile at the home of Tyndareus; in due time Agamemnon married Clytemnestra and Menelaus married Helen. In a late variation, Euripides's "Iphigenia at Aulis", Clytemnestra's first husband was Tantalus, King of Pisa; Agamemnon killed him and Clytemnestra's infant son, then made Clytemnestra his wife. In another version, her first husband was King of Lydia. The kings of
Greek mythology the existence of this corpus of data is a strong indication that many elements of Greek mythology have strong factual and historical roots. Mythical narration plays an important role in nearly every genre of Greek literature. Nevertheless, the only general mythographical handbook to survive from Greek antiquity was the "Library" of Pseudo-Apollodorus. This work attempts to reconcile the contradictory tales of the poets and provides a grand summary of traditional Greek mythology and heroic legends. Apollodorus of Athens lived from to and wrote on many of these topics. His writings may have formed the basis for the collection; however the