Also called Owein (in Welsh), Yvain is the son of Morgane and King Urien, he is the cousin of Calogrenant. He is the hero of a novel by Chrétien de Troyes, Yvain ou le Chevalier au lion (see Calogrenant).
In these adventures, he defeats a dark knight guardian of a fountain. In another adventure, he saves a lion attacked by a snake and becomes friends with this lion. In Thomas Malory's version, with Gauvain and Morholt, they meet three young ladies who take them on various adventures. This passage is taken up and transformed by Steinbeck who makes his young lady his fencing master. In the novel, he marries Laudine who is the wife of the knight guardian of the fountain and whom he killed.