* Marie de France specifically states in the prologue to her collection of lais, *Lais*, that she received her stories from Bretons. She writes, "I have taken these stories from Breton lays / and put them into French in the way I have been able."
* Chrétien de Troyes in his romance *Perceval, the Story of the Grail*, mentions that he received some of his material from "those who know the Bretons' tales". He also refers to a Breton source for his poem *Erec and Enide*.
While it is impossible to know for sure the extent to which these poets relied on Breton sources, their claims suggest a clear connection between their work and Breton oral tradition. This connection is further supported by the themes and motifs found in their works, which often reflect Celtic folklore and mythology.