Cassandra or Kassandra (Ancient Greek: Κασσάνδρα, pronounced [kassándra], also Κασάνδρα), (sometimes called Alexandra), was a woman in Greek mythology cursed to utter true prophecies, but never to be believed. In modern usage her name is employed as a rhetorical device to indicate someone whose accurate prophecies are not believed.
Cassandra was reputed to be a daughter of King Priam and Queen Hecuba of Troy.
The older and most common versions state that she was admired by the god Apollo, who sought to win her with the gift to see the future. She promised him her favors, but after receiving the gift, she went back on her word and refused the god. The enraged Apollo could not revoke a divine power, so he added to it the curse that though she would see the future, nobody would believe her prophecies.
Some later versions have her falling asleep in a temple, where the snakes licked (or whispered in) her ears so that she could hear the future.
Cassandra became a figure of epic tradition and of tragedy.