A knight who was seduced by the sorceress Acrasia in the Bower of Bliss.
He abandoned his wife, Amavia, and his infant son, Ruddymane. Amavia managed to free him from the Bower, but Acrasia had given him a poison that acted after his release and killed him. His death was avenged, and the Bower destroyed, by Sir Guyon.
Source
The Faerie Queene | Edmund Spenser, 1570-1599