Two entries with the name Gwen.
Arthur’s maternal grandmother, the daughter of Cunedda, in Welsh tradition.
In the Mabinogion story of the Dream of Rhonabwy, Gwenn is the name given to a mantle that made its wearer invisble. It was owned by Arthur’s servant Eiryn the Splendid.
In other sources it is simply referred to as Mantell, or as the Mantle of Invisibility, and was said to number among the Thirteen Treasures of Britain. Later tradition made King Arthur the owner of this treasure.
Breudwyt Rhonabwy | 13th century