 The Greek name Ὀρέστης, having become "Orestes" in Latin and its descendants, is derived from Greek ὄρος (óros, “mountain”) and ἵστημι (hístēmi, “to stand”), and so can be thought to have the meaning "stands on a mountain".In the Homeric telling of the story, Orestes is a member of the doomed house of Atreus which is descended from Tantalus and Niobe.Orestes is absent from Mycenae when his father, Agamemnon, returns from the Trojan War with the Trojan princess Cassandra as his concubine, and thus not present for Agamemnon's murder by Aegisthus, the lover of his wife, Clytemnestra.