In Greek mythology, Cassandra (Greek Κασσάνδρα, also Κασάνδρα) was the daughter of King Priam and Queen Hecuba of Troy. Her beauty caused Apollo to grant her the gift of prophecy. In an alternative version, she spent a night at Apollo's temple, at which time the temple snakes licked her ears clean so that she was able to hear the future (this is a recurring theme in Greek mythology, though sometimes it brings an ability to understand the language of animals rather than an ability to know the future). When Cassandra of Troy told him she wanted to stay a virgin, Apollo placed a curse on her so that she and all her descendants' predictions would not be believed. She is a figure both of the epic tradition and of tragedy.

Read more about Cassandra:  History, Agamemnon By Aeschylus, Modern Adaptations, Modern Usage, Greek and Latin Sources