Geoffrey of Monmouth (in Welsh: Gruffudd ap Arthur or Sieffre o Fynwy) (c. 1100 - c. 1155) was a clergyman and one of the major figures in the development of British history and the popularity of tales of King Arthur. Wikipedia
The definitive Wikipedia entry for Geoffrey Of Monmouth. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Geoffrey_of_Monmouth
Vol. 1. From the Beginnings to the Cycles of Romance. The Cambridge History of English and American Literature: An Encyclopedia in Eighteen Volumes. 1907–21 www.bartleby.com/211/0909.html