Cassandra is often thought of as the doomsayer of the Trojan people, according to Greek mythology. She was a chosen prophet of Apollo, who failed to either obey his instructions or return his love, depending upon the version of the myth. Thus Apollo gifted her with prophecy, but at the same time, he made sure that no one would ever believe anything she said.
As such, the prophecies of Cassandra are always true, but people around her treat her like a madwoman. As the daughter of King Priam of Troy, she prophesies the destruction and fall of Troy to the Athenians. Cassandra is, of course, ignored.
Cassandra becomes one of the “spoils” of war in Homer’s Iliad, belonging to first Ajax, and then to Agamemnon. One can trace her further mythology to two Classical Greek sources. She is mentioned in Oedipus Rex. However, her “featured” appearance occurs in Euripides’ Agamemnon
The Agamemnon includes Cassandra very briefly in the play, as she prophesies she will die soon, and that so will Agamemnon, one of the great leaders of the Athenian army. She is quite accurate as usual, and is murdered by Agamemnon’s wife, Clytemnestra.
In the play Cassandra has wonderful interaction and interplay with the chorus, and her scenes are both dramatic and tragic. It is rather exceptional to stand back and survey the curse of Cassandra. To never be believed while speaking truth is a rather fierce punishment, since it subjects one to the ridicule of others fairly constantly. The curse captured the imagination of the Greeks, since most could at some time relate to having been doubted.
The myth of Cassandra continued to be influential from a literary standpoint. Chaucer uses her in his great work Troilus and Criseyde. Beyond that there are references to Cassandra in numerous fictional pieces.
In film, the concept of Cassandra and a love for the masks of Greek theater are revived in the horror movie, Scream II. For a time, the main character, Sidney, is treated as a Cassandra, and no one will believe that a masked killer is again hunting her.
In the film, Sidney is also starring as Cassandra in a traditional production of Agamemnon. She becomes greatly frightened by a scene where she must predict her own death to the masked chorus. She is certain that she sees her masked assailant in the scene with the chorus, and is not believed. The scene is quite effective, and many believe it to be one of the scariest scenes of the film.
One may also hear someone referred to as a Cassandra, who predicts that bad things will happen, like the stock market dropping. This can be taken as either insult or compliment, depending upon usage. In correct usage, it means the person is likely right but is ruining other’s good moods with a less than cheerful picture of the future.
In psychology, the Cassandra Syndrome inaccurately makes use of the mythic origins of the prophetess. Here, it refers to people with a mistaken belief that they can foretell the future, as part of the psychosis. It is usually a part of schizophrenia or extreme mania, and is related to delusions of grandeur.