Agnes of Glanville was the first human woman to become a sorceress. She was a master of "air"–based magic, a member of the first Chapter and the author of the book The Secret of Secrets.
In The Witcher computer game[ | ]
Kalkstein mentions an "old friend", Agnes de Glanville when he is discussing making Raven's armour with Geralt. He mentions that her lair is still in one of the ancient crypts in the swamp cemetery.