In Greek mythology, Clytemnestra was the wife of Agamemnon, king of Mycenae, and the half-sister of Helen of Troy. With Agamemnon she was the mother of Orestes, Electra, and Iphigenia (and, in many accounts, Chrysothemis). She is infamous for murdering Agamemnon on his return from Troy — with or beside her lover Aegisthus — as revenge for the sacrifice of Iphigenia at Aulis, and later dies at the hands of her son Orestes.
Adapted from Wikipedia, "Clytemnestra" · CC BY-SA 4.0
I.Family and early life
Clytemnestra was the daughter of Tyndareus and Leda of Sparta. In the swan myth Zeus fathers Helen and Pollux while Tyndareus fathers Castor and Clytemnestra; her other sisters include Timandra, Philonoe, and Phoebe. Some sources give her a first husband, Tantalus (not the famous sinner), whom Agamemnon slew before taking her as wife, killing their child as well.
By Agamemnon she bore Orestes and the daughters Electra, Iphigenia, and Chrysothemis. Homer's Iliad names a daughter Laodice among Agamemnon's children, often identified with Electra.
II.Murder of Agamemnon
While Agamemnon fought at Troy, Clytemnestra took Aegisthus — himself of the cursed house of Atreus — as lover and co-ruler. On Agamemnon's return she and Aegisthus killed him, together with the Trojan captive Cassandra. Motive is usually the sacrifice of Iphigenia at Aulis and resentment of Cassandra; Aegisthus also avenges Atreus's crimes against Thyestes.
Homer's Iliad leaves her role muted; the Odyssey has Agamemnon's ghost recount her part in the murder. Aeschylus's Agamemnon makes her the principal agent: she nets Agamemnon in the bath and strikes him down, then boasts over the corpses. Sophocles and Euripides vary the balance of guilt between queen and lover.
III.Death and reception
Years later Orestes, often aided by Electra and Pylades, kills Aegisthus and Clytemnestra in vengeance. Aeschylus's Libation Bearers and Eumenides turn the matricide into a trial of blood-guilt before Athena and the Areopagus; Sophocles's and Euripides's Electra plays dramatize Electra's role and the aftermath.
Clytemnestra remains a central figure of Greek tragedy and later opera, psychology, and feminist rereading — the wife who answers a husband's wartime crime with household violence, and who dies as both murderer and victim of the Atreid curse.