The Lais of Marie de France
Who or what is Lanval's sweetheart?
?
?
Lanvel's sweetheart is a beautiful, mystical lady. He ends up with her after she saves him from his trial in Arthur's court, and together they disappear into the realm of Avalon.
http://www.gradesaver.com/the-lais-of-marie-de-france/study-guide/character-list/