Clytemnestra is a daughter of Tyndareus and Leda. She was first married to Tantalus. When Agamemnon, the kin of Mycenae, killed him and their young child together, he married Clytemnestra. She bore him several children: Iphigeneia, Electra and Orestes.
At Aulis, Agamemnon was forced to sacrifice Iphigeneia. As a pretext for her to come from Mycenae, he told Iphigeneia that she was to marry Achilles. When Clytemnestra found out about this, she developed a powerful hatred for her husband.
While Agamemnon was fighting in the Trojan War, Clytemnestra takes Aegisthus as her lover. When Agamemnon returns from Troy, the two murder him, along with his new mistress Cassandra and their two children. Aegisthus rules as the king of Mycenae for seven years.
Eventually, however, Orestes, Agamemnon's son, returns. With the help of his sister Electra, they kill Aegisthus and Clytemnestra.