Answer: The Agamemnon, Choephori, and Eumenides were the last tragedies composed by Aeschylus, and were produced in 458 [B.C.], two years before his death, along with the satiric drama Proteus. The tetralogy as a whole was called the Oresteia, a name which, whether due to Aeschylus or not, appears to have been in use at any rate as early as the time of Aristophanes. The contents of the Proteus are unknown, and its connection with the preceding tragedies obscure; but it probably dealt with the fortunes of Menelaus, the brother of Agamemnon, and related the story of his detention on the coast of Egypt, and his rescue by the help of Proteus, the sea-god....Read More.