ORESTES, in Greek legend, son of Agamemnon and Clytaemnestra. According to the Homeric story he was absent from Mycenae when his father returned from the Trojan War and was murdered by Aegisthus. Eight years later he returned from Athens and revenged his father's death by slaying his mother, and her paramour (Odyssey, iii. 306; xi. 542). According to Pindar (Pythia, xi. 25) he was saved by his nurse, who conveyed him out of the country when Clytaemnestra wished to kill him. The tale is told much more fully and with many variations in the tragedians. He was preserved by his sister Electra from his father's fate, and conveyed to Phanote on Mount Parnassus, where King Strophius took charge of him. In his twentieth year he was ordered by the Delphic oracle to return home and revenge his father's death. According to Aeschylus, he met his sister Electra before the tomb of Agamemnon, whither both had gone to perform rites to the dead; a recognition takes place, and they arrange how Orestes shall accomplish his revenge. Orestes, after the deed, goes mad, and is pursued by the Erinyes, whose duty it is to punish any violation of the ties of family piety. He takes refuge in the temple at Delphi; but, though Apollo had ordered him to do the deed, he is powerless to protect his suppliant from the consequences. At last Athena receives him on the acropolis of Athens and arranges a formal trial of the case before twelve Attic judges. The Erinyes demand their victim; he pleads the orders of Apollo; the votes of the judges are equally divided, and Athena gives her casting vote for acquittal. The Erinyes are propitiated by a new ritual, in which they are worshipped as Eumenides (the Kindly), and Orestes dedicates an altar to Athena Areia. With Aeschylus the punishment ends here, but, according to Euripides, in order to escape the persecutions of the Erinyes, he was ordered by Apollo to go to Tauris, carry off the statue of Artemis which had fallen from heaven, and bring it to Athens. He repairs to Tauris with Pylades, the son of Strophius and the intimate friend of Orestes, and the pair are at once imprisoned by the people, among whom the custom is to sacrifice all strangers to Artemis. The priestess of Artemis, whose duty it is to perform the sacrifice, is his sister Iphigeneia (q.v.). She offers to release Orestes if he will carry home a letter from her to Greece; he refuses to go, but bids Pylades take the letter while he himself will stay and be slain. After a conflict of mutual affection, Pylades at last yields, but the letter brings about a recognition between brother and sister, and all three escape together, carrying with them the image of Artemis. After his return to Greece, Orestes took possession of his father's kingdom of Mycenae, to which were added Argos and Laconia. He is said to have died of the bite of a snake in Arcadia. His body was conveyed to Sparta for burial (where he was the object of a cult), or, according to an Italian legend, to Aricia, whence it was removed to Rome (Servius on Aeneid, ii. 116). The story of Orestes was the subject of the Oresteia of Aeschylus (Agamemnon, Choephori, Eumenides), of the Electra of Sophocles, of the Electra, Iphigeneia in Tauris, and Orestes, of Euripides. There is extant a Latin epic poem, consisting of about 1000 hexameters, called Orestes Tragoedia, which has been ascribed to Dracontius of Carthage.
Orestes appears also as a central figure in various legends connected with his madness and purification, both in Greece and Asia. In these Orestes is the guilt-laden mortal who is purified from his sin by the grace of the gods, whose merciful justice is shown to all persons whose crime is mitigated by extenuating circumstances. These legends belong to an age when higher ideas of law and of social duty were being established; the implacable blood-feud of primitive society gives place to a fair trial, and in Athens, when the votes of the judges are evenly divided, mercy prevails.
The legend of Orestes is the subject of a lengthy monograph by T. Zielinski, "Die Orestessage und die Rechtfertigungsidee" in Neue Jahrbücher für das klassische Altertum, ii. (1899). Orestes, according to Zielinski, is the son of the sky-god Zeus-Agamemnon, who overcomes his wife the earth-goddess Gaia-Clytaemnestra; with the assistance of the dragon Aegisthus, she slays her husband, whose murder is in turn avenged by his son. The religion of Zeus is then reformed under the influence of the cult of Apollo, who slays the dragon brought up by the earth-goddess on Parnassus, the seat of one of her oldest sanctuaries. Parnassus becomes the holy mountain of Apollo, and Orestes himself an hypostasis of Apollo "of the mountain," just as Pylades is Apollo "of the plain"; similarly Electra, Iphigeneia and Chrysothemis are hypostases of Artemis. Zeus being firmly seated on his throne as the result of the slaying of the dragon by Orestes, the theological significance of the myth is forgotten, and the identifications Zeus-Agamemnon and Gaia-Clytaemnestra are abandoned. In the Homeric Oresteia the soul of the murdered wife has no claim to vengeance, and Orestes rules unmolested in Argos. But the Apolline religion introduces the theory of the rights of the soul and revenge for bloodshed. Apollo, who has urged Orestes to parricide and has himself expiated the crime of slaying the dragon, is able to purify others in similar case. Hence Orestes, freed from the guilt of blood, is enabled to take possession of the throne of his father. This is the Delphic Oresteia. But a new idea is introduced by the Attic Oresteia. The claim that Apollo can in every case purify from sin is met by Athens with a counterclaim on behalf of the state. It is the community of which murdered and murderer were members which has the right to exact revenge and retribution, an idea which found expression in the foundation of the Areopagus. If the accused is acquitted, the state undertakes to appease the soul of the murdered person or its judicial representative, the Erinys.
Others attach chief importance to the slaying of Neoptolemus (Pyrrhus) by Orestes at Delphi; according to Radermacher (Das Jenseits im Mythos der Hellenen, 1903), Orestes is an hypostasis of Apollo, Pyrrhus the principle of evil, which is overcome by the god; on the other hand, Usener (Archiv für Religionswesen, vii., 1899, 334) takes Orestes for a god of winter and the underworld, a double of the Phocian Dionysus the "mountain" god (among the Ionians a summer-god, but in this case corresponding to Dionysus μελαναιγίς), who subdues Pyrrhus "the light," the double of Apollo, the whole being a form of the well-known myths of the expulsion of summer by winter. S. Reinach (reviewing P. Mazan's L'Orestie d'Eschyle, 1902) defends the theory of Bachofen, who finds in the legend of Orestes an indication of the decay of matriarchal ideas.
See article by Hofer in Roscher's Lexikon der Mythologie; A. Olivieri, "Sul mito di Oreste nella letteratura classica" (with a section on modern literature) in Rivista di Filologia, xxvi. (1898), and Jebb's edition of the Electra of Sophocles.