Evaine is a minor character in Arthurian legend who appears in the Old French roman Lancelot do Lac (c.1215-20; incorporated into the Vulgate Lancelot). She is the sister of Lancelot's mother Elaine. She and her sister are married to brother kings (Bors, King of Gaul and Ban, King of Benoic, respectively) and suffer parallel fates, both women losing their husbands and sons and then entering the same convent. In Evaine's case, she is widowed when her husband dies, either in battle or from grief after learning about his brother's death; feeling unsafe from attack, she flees with her two sons, Lionel and Bors the Younger (who later achieves the Holy Grail), but tragically, her boys are captured and imprisoned by the enemy (Claudas). Evaine alone manages to escape, and goes to her sister who, spurred by her own personal sorrow, has taken the vow as a nun.
Evaine follows her into the religious life and passes many years at the abbey, incessantly tormented with worry over her sons. Finally a former knight called the Black Friar (a.k.a. Adragain) visits the abbey and informs her that her sons are still alive — and Elaine's son too, who has been fostered by the Lady of the Lake. The Lady resolves to rescue and look after Evaine's sons also, and one of her damsels frees them and spirits them to her underwater home. Evaine, who has grown pale and ill from the fraught years, wishes to know that her sons are alive and safe; that night she has a vision of her sons playing in the Lady of Lake's garden with Elaine's Lancelot, and wakes up to find their names (Lionel, Bors and Lancelot) written on her right hand. She dies in peace, knowing that her sons and nephew are safe.