Electra

1. Daughter of Oceanus and Tethys, mother of Dardanus, Iasion and Harmonia, by Zeus.
2. A Pleiade or Oceanid, mother of Iris and the Harpies by Thaumas.
3. (Most famous "Electra") Daughter of Agamemnon and Clytemnestra. Alternative: Laodice

According to the Homeric story, Electra (daughter of Agamemnon and Clytemnestra) was absent from Mycenae when her father, King Agamemnon, returned from the Trojan War and was murdered by Aegisthus, Clytemnestra's lover, and/or by Clytemnestra herself. Aegisthus and Clytemnestra also killed Cassandra, Agamemnon's lover.

Eight years later Electra returned from Athens with her brother, Orestes. (Odyssey, iii. 306; X. 542). According to Pindar (Pythia, xi. 25), Orestes was saved by his old nurse or by Electra, and was taken to Phanote[?] on Mount Parnassus, where King Strophius took charge of him.

In his twentieth year, Orestes was ordered by the Delphic oracle to return home and avenge his father's death. According to Aeschylus, he met Electra before the tomb of Agamemnon, where both had gone to perform rites to the dead; a recognition took place, and they arranged how Orestes should accomplish his revenge.

Orestes, after the deed (sometimes with Electra helping), goes mad, and is pursued by the Erinyes, or Furies), whose duty it is to punish any violation of the ties of family piety. Electra is not hounded by the Erinyes.

Orestes takes refuge in the temple at Delphi. Even though Apollo (to whom the Delphic temple was dedicated) had ordered him to do the deed, he is powerless to protect Orestes from the consequences of his actions.

At last Athene (also known as Areia) 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.

Later, Electra married Pylades, Orestes' close friend and son of King Strophius (the same one who had cared for Orestes while he hid from his mother and her lover).

Aeschylus, Oresteia[?]; Euripides, Electra; Orestes; Apollodorus, Epitome VI, 23-28.