In Greek mythology, Perseus is the legendary founder of Mycenae and of the Perseid dynasty, who, alongside Cadmus and Bellerophon, was the greatest Greek hero and slayer of monsters before the days of Heracles. He beheaded the Gorgon Medusa for Polydectes and saved Andromeda from the sea monster Cetus. He was the son of Zeus and the mortal Danaë, as well as the half-brother and great-grandfather of Heracles. Because of the obscurity of the name Perseus and the legendary character of its bearer, most etymologists presume that it might be pre-Greek; however, the name of Perseus’ native city was Greek and so were the names of his wife and relatives. There is some idea that it descended into Greek from the Proto-Indo-European language. In that regard Robert Graves has proposed the only Greek derivation available. Perseus might be from the Greek verb, “πέρθειν” (perthein), “to waste, ravage, sack, destroy”, some form of which appears in Homeric epithets. According to Carl Darling Buck (Comparative Grammar of Greek and Latin), the –eus suffix is typically used to form an agent noun, in this case from the aorist stem, pers-. Pers-eus therefore is a sacker of cities; that is, a soldier by occupation, a fitting name for the first Mycenaean warrior.