Labiane
The niece of King Mark of Cornwall. Her brother, Aldret (Andred), was Mark’s adviser.
Mark raped her, begetting Meraugis, who later became a Knight of the Round Table. Mark locked Ladiana in a tower when he discovered that she was pregnant. After she gave birth to Meraugis, Mark slew her and left her body to be eaten by wild beasts.
Source
Post-Vulgate Queste del Saint Graal | 1230-1240