Perseus, Perseos, or Perseas (Greek: Περσεύς, Περσέως, Περσέας), the legenary founder of Mycenae and of the Perseid dynasty there, was the first of the mythic heroes of Greek mythology whose exploits in defeating various archaic monsters provided the founding myths in the cult of the Twelve Olympians. Perseus was the hero who killed Medusa and claimed Andromeda, having rescued her from a sea monster.