The Legend of King Arthur was made popular by Geoffrey of Monmouth in his History of the Kings of Britain written in 1135 AD. Chretien de Troyes and Malory later embellished Geoffrey of Monouth's story. These authors drew upon earlier histories including History of the Britons by Nennius, the Annales Cambriae, and the Complaining Book of Gildas, a Welsh monk from the 6th century, as well as local histories, poetry, Celtic mythology and traditions.