The question: How old is Greek mythology? may at first sight seem idle, for Greek mythology is obviously of many different ages. For example, many genealogies and eponymous heroes created for political purposes are late, such inventions having been made through the whole historical age of Greece; yet most of them are earlier than the very late myths like the campaigns of Dionysus, or the great mass of the metamorphoses, especially the catasterisms, which were invented in the Hellenistic age.