 The 12th-century French writer Chrétien de Troyes, who added Lancelot and the Holy Grail to the story, began the genre of Arthurian romance that became a significant strand of medieval literature.In these French stories, the narrative focus often shifts from King Arthur himself to other characters, such as various Knights of the Round Table.Arthurian literature thrived during the Middle Ages but waned in the centuries that followed until it experienced a major resurgence in the 19th century.