Brother of Sansfoy, a pagan knight slain by the Red Cross Knight, and of Sansloy.
Encountering the Red Cross Knight at the House of Pride, Sansjoy demanded single combat. Sansjoy received assistance from the evil witch Duessa. When the Red Cross Knight appeared to be winning, however, Sansjoy was carried away in a black cloud. The cloud took him to Hades, where his wounds were treated.
See also
Hades | Myths and Legends
Source
The Faerie Queene | Edmund Spenser, 1570-1599