Cutting your nose off to spite your face...
The phrase is believed to have originated from a event that was said to have taken place in AD 867: Viking pirates from Sjaelland and Uppsala landed in Scotland and raided the monastery of Coldingham. When news of the raid reached Aebbe the Younger, the Mother Superior, she gathered her nuns together and urged them to disfigure themselves, so that they might be unappealing to the Vikings. In this way, they hoped to protect their chastity. St. Aebbe accomplished this by cutting off her nose and upper lip. The nuns proceeded to do the same. The Viking raiders were so disgusted by the scene that they burned the entire building to the ground.
Ironically, the phrase as understood today doesn't precisely apply to Aebbe. After all, Aebbe did not cut off her nose in an effort to "spite her face".
The expression has since come to refer to pointlessly self-destructive actions motivated purely by malevolence. For example, if a man were angry at his wife, he might burn down their house to punish her. Of course, this would be an example of cutting off his nose to spite his face, as in the process of burning down her house he would also be destroying his home, along with all his personal possessions.
(from wiki)
I thought that was really interesting.
