It tells the story of Owain and his overthrowing of the Knight of the Fountain in "The Lady of the Fountain."  
It tells the story of Owain and his overthrowing of the Knight of the Fountain in "The Lady of the Fountain."  It also tells the story of "Peredur, Son of Evrawg," a na?e child who grows up to be a matchless knight.  It originally consisted of only the first four tales, "Math, Son of Mathonwy," "Manawydan, Son of Llyr," "Branwen, Daughter of Llyr," and "Pwyll, Prince of Dyved," as compiled by Lady Charlotte Guest, but was augmented by earlier unknown authors who related further Arthurian adventures, such as "Kilhwch and Olwen."  FTP, identify this collection of Welsh tales.
It tells the story of Owain and his overthrowing of the Knight of the Fountain in "The Lady of the Fountain."  
The Mabinogion