Agamemnon's father Atreus was murdered by Aegisthus, who took possession of the throne of Mycenae and ruled jointly with his father Thyestes. During this period Agamemnon and Menelaus took refuge with Tyndareus, king of Sparta. There they respectively married Tyndareus' daughters Clytemnestra and Helen. Agamemnon and Clytemnestra had four children: three daughters, Iphigeneia, Electra, and Chrysothemis, and one son, Orestes.
Menelaus succeeded Tyndareus in Sparta, while Agamemnon, with his brother's assistance, drove out Aegisthus and Thyestes to recover his father's kingdom. He extended his dominion by conquest and became the most powerful prince in Greece.
However, Agamemnon's family history, dating back to legendary king Pelops, had been marred by rape, murder, and treachery. The Greeks believed this violent past brought misfortune upon the entire House of Atreus.
The Trojan War
Agamemnon gathered together the Greek forces to sail for Troy. Preparing to depart from Aulis, a port in Boeotia, Agamemnon's army incurred the wrath of the goddess Artemis by slaying an animal sacred to her. Misfortunes including a plague and a lack of wind prevented the army from sailing; finally, the prophet Calchas announced that the wrath of the goddess could only be propitiated by the sacrifice of Iphigeneia (daughter of Agamemnon). Classical dramatizations differ on how willing either father or daughter were to this fate, but Agamemnon did eventually sacrifice Iphigenia. Her death appeased Artemis and the Greek army set out for Troy. Several alternatives to the human sacrifice have been presented in Greek mythology. Other sources claim Agamemnon was prepared to kill his daughter, but Artemis accepted a deer in place of Iphigenia, and whisked her to Tauris in the Crimea. Hesiod said she became the goddess Hecate.
Agamemnon was the commander-in-chief of the Greeks during the Trojan War. During the fighting, Agamemnon killed Antiphus. Agamemnon's teamster, Halaesus, later fought with Aeneas in Italy. The Iliad tells the story of the quarrel between Agamemnon and Achilles in the final year of the war. Agamemnon took an attractive slave and spoil of war Briseis from Achilles. Achilles, the greatest warrior of the age, withdrew from battle in revenge and nearly cost the Greek armies the war.
Although not the equal of Achilles in bravery, Agamemnon is a dignified representative of kingly authority. As commander-in-chief, he summons the princes to the council and leads the army in battle. He takes the field himself, and performs many heroic deeds until he is wounded and forced to withdraw to his tent. His chief fault is his overweening haughtiness. Due to an over-exalted opinion of his position, which leads him to insult Chryses and Achilles, thereby bringing great disaster upon the Greeks.
Return to Greece
After a stormy voyage, Agamemnon and Cassandra landed in Argolis or were blown off course and landed in Aegisthus' country. Aegisthus, who in the interval had seduced Clytemnestra, invited him to a banquet at which he was treacherously slain. According to the account given by Pindar and the tragedians, Agamemnon was slain by his wife alone in a bath, a piece of cloth or a net having first been thrown over him to prevent resistance. Clytemnestra also killed Cassandra. Her wrath at the sacrifice of Iphigenia, and her jealousy of Cassandra, are said to have been the motives of her crime. The murder of Agamemnon was avenged by his son Orestes.
The fortunes of Agamemnon have formed the subject of numerous tragedies, ancient and modern, the most famous being the Oresteia of Aeschylus. In the legends of the Peloponnesus, Agamemnon was regarded as the highest type of a powerful monarch, and in Sparta he was worshipped under the title of Zeus Agamemnon. His tomb was pointed out among the ruins of Mycenae and at Amyclae.
In works of art there is considerable resemblance between the representations of Zeus, king of the gods, and Agamemnon, king of men. He is generally characterized by the sceptre and diadem, the usual attributes of kings.