Who is Yonec from The Lais of Marie de France and what is their importance?

Yoneca ppears in Yonec. He is the son of the lady of Caerwent and Muldumarec. He has grown into a valiant knight by the end of the story when he exacts revenge on the lord of Caerwent for killing his father. Yonec assumes the lordship over Muldumarec's kingdom.