Marie de France

Lanval
Slip-shod knight makes good

In the character of Lanval, author Marie De France creates the character of the unlikely hero. Lanval is the least thought of knight in the court of King Arthur, he doesn't even get paid for his service! Marie states that the other knights are jealous of Lanval's handsome figure and his courage, but she has to be using understatement in order to make a point. If Lanval was the bravest and most handsome knight in the court of King Arthur, surely Arthur would remember him when payday rolled around.
Lanval leaves to seek his fortune, meets and falls in love with a very beautiful fairy queen. She will give him everything she ever dreamed of if he does not tell anyone where it comes from or about her. He cannot keep his promise and tells King Arthur's wife that he loves a woman so much more beautiful that the ugliest servant girl in the Fairy realm is better looking than her! He is then tried by all of King Arthur's vassals and the Fairy Queen has to ride in and save his neck.
Many parts of this story remind me of small fairy tales popularized by the Brothers Grimm. The unlikelyness of Lanval being a great knight reminds me of the story of the Brave Little Tailor in that no one in the town expected him to defeat a giant, though he claimed "seven with one blow"(http://grimm.thefreelibrary.com/Fairy-Tales/18-1). No one believed that he was talking about flies! Until the Little Tailor proves that he has the smarts to outwit a giant, he is very much like Lanval, no one beleives the tales of a beatuiful Fairy Queen that has fallen in love with him.