CASSIOPEIA, in fabulous history, wife to Cepheus, king of Ethiopia, and mother of Andromeda. She thought herself more beautiful than the Nereides, who desired Neptune to revenge the affront; so that he sent a sea monster into the country, which did much mischief. To appease the god, her daughter Andromeda was exposed to the monster, but was rescued by Perseus, who obtained leave of Jupiter that Cassiopeia might be placed after her death among the stars; and hence the constellation of that name.