Helen, commonly known as Helen of Troy and sometimes as Helen of Sparta, is a figure in Greek mythology said to have been the most beautiful woman in the world. She was believed to have been the daughter of Zeus by Leda or Nemesis, and the sister of Clytemnestra, Castor, Pollux, Philonoe, Phoebe and Timandra. She was first married to King Menelaus of Sparta "who became by her the father of Hermione, and, according to others, of Nicostratus also." Her subsequent marriage to Paris of Troy was the most immediate cause of the Trojan War.