Who is Arthur's Queen from The Lais of Marie de France and what is their importance?

Arthur's Queen appears in Lanval. Queen Guinivere is also a legendary character from the tales of King Arthur. The queen makes an advance toward Lanval, but is spurned. She then tells Arthur that it was Lanval who made the advance to her, then insulted her when she refused. It is Guinivere's deception that sets up the main conflict in the story.