What role does Cassandra assume in the play Agamemnon?

Cassandra is the daughter of the Trojan King Priam. She was a priestess of Apollo and Apollo gave her the gift of true prophecy but when she refused to sleep with him, cursed her so that even though she always spoke the truth, she would never be believed. When the Greeks conquered Troy, she was taken as a war prize (i.e. seized and raped) first by Ajax and then by Agamemnon.

She has two roles in the play. First, her presence inflames Clytemnestra's sense of mistreatment. After Agamemnon killed their daughter Iphigenia and spent ten years away at Troy, he now returns home accompanies by a pretty young woman, Cassandra, something his neglected wife does not appreciate. Second, in a dramatic scene with the chorus, Cassandra foretells the death of Agamemnon and her own death, and suggests that the death of Clytemnestra with avenge both of their deaths.

From a literary perspective, Cassandra 's prophecy heightens the dramatic tensions and sense of impending horror in the play. Her intense response to her visions adds to the sense of horror at murders which the audience will not see performed onstage. She becomes a vicarious witness to the two deaths even before they happen and her vivid description and reaction evoke the fear and pity that Aristotle sees as the essence of tragedy.