Fringilla Vigo was a Nilfgaardian sorceress and a member of the Lodge of Sorceresses along with her fellow countrywoman, Assire var Anahid.
She was also the second cousin of Anna Henrietta of Toussaint. She was a woman with natural grace, green eyes and close-cropped black hair. During the First Northern War Fringilla fought for Nilfgaard at the Battle of Sodden Hill where she blinded Yennefer who was fighting on the opposing side.
When Geralt and his team reached Toussaint, Fringilla embarked on a romantic relationship with Geralt and did everything in her power to keep him from leaving the castle. While the witcher did develop some feelings for her, he never quite was able to put Yennefer out of his mind, even going so far as to use Yennefer's name instead of Fringilla's in the throes of passion.