Agamemnon's wife and the daughter of the Spartan king Tyndareus and Leda, as well as the sister of Helen of Troy and Timandra. Because her father had neglected a certain sacrifice to Aphrodite the goddess cursed him, saying all three daughters would be adulteresses.Clytemnestra was initially married to Thyestes' son Tantalus who was an old man, and who was killed by either Atreus or Agamemnon soon after the wedding.
With her second husband Agamemnon Clytemnestra had two sons, Orestes and Chrysothemis, and two daughters, Electra and Iphigenia.
Initially, she loved her husband, but when he sacrificed Iphigenia to the goddess Artemis she swore to kill him. On his departure Agamemnon left a singer in his palace to entertain Clytemnestra. As long as the singer was there, she did not fall for Aegisthus, but Aegisthus took the singer away, thus making Clytemnestra easy to seduce.
When Agamemnon returned from Troy Clytemnestra and her lover Aegisthus murdered him and Cassandra, whom he had brought with him as a prisoner of war and mistress.
Together with Aegisthus she ruled Mycenae for seven years, and they had three children: Erigone, Aletes and Helen. They were both killed by her son Orestes.