Helen
2 of the 7 encyclopedias on this shelf carry an entry for Helen. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
in Greek legend, the most beautiful woman of antiquity. Her home was at Sparta. She was the daughter of Zeus and Leda. In girlhood, the hero Theseus ran away with her to Athens. Her brother Castor brought her back to Sparta. She was finally given in wedlock to Menelaus, the king. Paris, son of Priam, king of Troy, heard of her beauty, and, with the aid of the goddess Aphrodite, won her love and fled with her to Troy. Here she abode for twenty years. Menelaus, her husband, called all Greece to arms and precipitated the Trojan War. After the death of Paris, and ere the destruction and sack of Troy, she became the mate of the Greek warrior, Deiphobus. When Troy fell Menelaus escorted her with honor to her Sparta home. Of all the characters in Grecian legend Helen was the most beautiful, the most desired, and the least securely possessed. Even after death, so runs the story, her shade was mated with that of Achilles on the Stygian shore. See Troy ; Paris ; Menelaus
Collier's New Encyclopedia (1921)
in classic fable, the daughter of Jupiter and Leda, of Jupiter and Nemesis, or of the King Tyndareus and Leda, his wife, according to the various statements of the poets, was the most beautiful woman of her time , and married Menelaus, King of Sparta. Her guilty elopement with Paris , one of the sons of Pr Priam, King of Troy, who had been sent to Lacedæmon as ambassador, led to the Trojan War, and the destruction, after 10 years' siege, of Troy . On the death of Paris, she married his brother Deiphobus, and when the city was at last sacked, returned to Sparta with her husband Menelaus. Being banished from Sparta on the death of Menelaus, she retired to the island of Rhodes , where, having excited the envy of Polyxo, the queen of the isle, she was tied to a tree and strangled.