In the Iliad, she is described as the loveliest of the daughters of Priam (King of Troy), and gifted with prophecy. The god Apollo loved her, but she spurned him. As a punishment, he decreed that no one would ever believe her. So when she told her fellow Trojans that the Greeks were hiding inside the wooden horse...well, you know what happened.
...years old today, and actually feeling great about it! I'm such a lucky girl, with wonderful friends. And if I should ever feel depressed (or skeptical, like Manon) about the pile-up of years, I can always remember that my alter-ego, Cassandra, is only 9 1/2!