An evil, ugly witch in Spenser’s The Faerie Queene who allegorically represents Mary Queen of Scots and Catholicism.
Appearing in the guise of a beautiful maiden named Fidessa, she lured the Red Cross Knight from the quest assigned to him by Gloriana, the Fairy Queen. Just after she seduced him, however, the giant Orgoglio captured them both, threw Red Cross in a dungeon, and made Duessa his mistress. Arthur eventually stormed Orgoglio’s castle, killed the giant, and stripped Duessa, exposing her as a disgusting hag.
She later became the amie of the knight Paridell. She was eventually convicted of attempting to overthrow a queen named Mercilla, and she was executed.
Source
The Faerie Queene | Edmund Spenser, 1570-1599