To elaborate slightly on that etymology, the original aegis was a shield covered with a goatskin, technically supposedly belonging to Zeus (exactly how or why is obscure in our sources) that he gave to Athena to bear for him when not in battle. She carried everywhere, however, and went even so far as to trick out with Medusa's head, thus making it for all practical purposes her own. Speculations that the Zeus connection was a later invention make her more subordinate would not be out of line.
(no subject)
Date: 2014-02-14 02:30 pm (UTC)---L.