The Agamemnon (Ancient Greek: Ἀγαμέμνων) is a tragedy by Aeschylus, the first play of the Oresteia, a sequence which won the dramatic competition at Athens in its original production of 458 BCE. Together with its sequels, The Libation Bearers (Choephoroi) and the Eumenides, it forms the only trilogy from classical Attic drama to survive intact.
The plot centres on Agamemnon's return from Troy with his concubine Cassandra, whose gift of prophecy allows her to foresee that they will be murdered by his wife Clytemnestra, and her lover Aegisthus.
Free online texts
Gutenberg: The House of Atreus; Being the Agamemnon, the Libation bearers, and the Furies, translated by E.D.A. Morshead. Multiple formats.
Gutenberg: Agamemnon, verse translation by Gilbert Murray. Multiple formats.
Internet Archive: The Plays of Aeschylus, translated by Walter Headlam and C.E.S. Headlam. Multiple formats.
Loebulus. L146 - Aeschylus -- Agamemnon. Libation-Bearers. Eumenides. Fragments. PDF of public domain Loeb edition.
Perseus: Agamemnon, translated by Robert Browning (1889). TXT and XML formats.
Poetry in Translation: Agamemnon, translated by George Theodoridis (2009). Multiple formats.
University of Adelaide (Internet Archive): Agamemnon, translated by E.D.A. Morshead. Multiple formats.
Vancouver Island University: Agamemnon, translated by Ian Johnston. HTML format.
Ancient History Encyclopedia: Agamemnon, by Donald L. Wasson.
History of Ancient Greece: Early Tragedy and Aeschylus, podcast by Ryan Stitt.
Literature and History: Episode 26 - Ancient Greek Theater. Podcast.
Literature and History: Episode 27 - The Bloody King - The Oresteian Trilogy, Part 1 - Agamemnon. Podcast.
Vancouver Island University: Lecture on the Oresteia, by Ian Johnston.
The Great Conversation: Further reading at Tom's Learning Notes
Homer: The Iliad.
Homer: The Odyssey.
Aristotle: The Poetics.
A.E. Haigh: The Tragic Drama of the Greeks (1896).
Ancient Greek resources: Learn to read Greek classics in the original.