Aegisthus (/ɪˈdʒɪsθəs/; Ancient Greek: Αἴγισθος; also transliterated as Aigisthos, [ǎi̯ɡistʰos]) was a figure in Greek mythology. Aegisthus is known from two primary sources: the first is Homer's Odyssey, believed to have been first written down by Homer at the end of the 8th century BC, and the second from Aeschylus's Oresteia, written in the 5th century BC. Aegisthus also features heavily in the action of Euripides's Electra (c. 420 BC), although his character remains offstage.