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 libretti for many of Handel's and Mozart's operas. By the end of the 18th century, Romanticism initiated a surge of enthusiasm for all things Greek, including Greek mythology. In Britain, new translations of Greek tragedies and Homer inspired contemporary poets (such as Alfred Lord Tennyson, Keats, Byron and Shelley) and painters (such as Lord Leighton and Lawrence Alma-Tadema). Christoph Gluck, Richard Strauss, Jacques Offenbach and many others set Greek mythological themes to music. American authors of the 19th century, such as Thomas Bulfinch and Nathaniel Hawthorne, held that the study of the classical myths was essential to the understanding of