Ulrich von Zatzikhoven writes in both prose and poetry of Lancelot was the only child of King Ban (Pant) of Benoic (Genewis) and his queen Helaine (Clarine). His father was driven from his kingdom, and the King and Queen leave with their infant child. The king dies of a broken heart and the child is carried off by the Lady of the Lake, who brings the boy up in her mysterious kingdom. In the German poem this is an “Isle of Maidens,” where there are no men. In the prose version the Lady's court has gallant knights; and Lancelot has his cousins, Lionel and Bors (sons of his father's younger brother Bors) with him. When he reaches the age of manhood, the young Lancelot goes out into the world, knowing neither his own name nor who his parents were. In the prose version of Lancelot he arrives at Arthur's court where the Lady of the Lake asks that he be knighted.
He rides in search of adventure, accompanied by a woman who later abandons him, but he eventually learns his true name and parents. He eventually regains his rightful heritage. Arthur and Lancelot move against Cladius, who then flees into exile.
In Lanzelet (the poetry version), Lancelot reigns over a country inherited though his wife Iblis and both Lancelot and his wife live to see their grand-children, and both die on the same day in old age.
In the prose version, Lancelot, from his first sight of Guinevere (who is considerably older than he) falls madly in love with her. He frees her from Meleagant, who had kidnapped her. He recovers his kingdom from Claudas, but prefers to remain a knight of King Arthur's court. His his cousins and illegitimate half-brother Hector de Maris are knights at King Arthur's court. Tricked into sleeping with the Fisher King's daughter (called Elaine in a few later texts), he becomes the father of Galahad. He takes partin the quest for the Holy Grail , but gets only a fleeting glimpse of the sacred Vessel because of his years in sin. His relationship with Guenevere is revealed to Arthur by the sons of King Lot, Gawain, Guerrehet and Gaheriet (in Malory Gawain, Gaheris, and Gareth). Surprised in bed with the queen, Lancelot escapes, and the queen is condemned to be burnt alive. But Lancelot returns to rescue her, though in the process many of Arthur's knights, including three of Gawain's brothers, are killed. Gawain makes war on Lancelot. . But this war is interrupted when Arthur goes off to Gaul to battle and defeat the Romans who had invaded it. Whilst Arthur is in Gaul news reaches him of Mordred's treachery. Arthur is killed in the final battle against Mordred. But Lancelot, who in this version, took no part in the last battle, outlives both king and queen, retiring to a hermitage, where he ends his days.
Chrétien de Troyes' treatment of Lancelot is different in different works. In Erec and Enide, his earliest poem, Lancelot's name appears as third on the list of the knights of Arthur's court. (Gawain is the most senior knight here, and Erec, the hero of the tale, is second, so third position shows a high status for Lancelot). In Cligés Lancelot makes an appearance as one of the knights the story's hero must vanquish. In Le Chevalier de la Charrette, which was written after Cligés, Lancelot is the hero of the poem, the best knight of the court and also lover of the queen. In Perceval, le Conte du Graal, Chrétien's last work, he does not feature at all even though much of the action happens at King Arthur's court. In the Continuations added later to Chrétien's unfinished work the role assigned to Lancelot is modest. Among the fifteen knights selected by Arthur to accompany him to Chastel Orguellous he only ranks ninth. In a Tristan episode added by Gerbert de Montreuil in his continuation, Lancelot is just one of the knights publicly overthrown and shamed by Tristan.
Nowhere other than in Le Chevalier de la Charette is Lancelot treated with the importance given to him in the prose romances. Welsh stories do not mention him. Early Italian records, which use the names of Arthur and Gawain, do not mention Lancelot. Chrétien states that he composed the poem about Lancelot and Guinevere at the request of Countess Marie de Champagne. Marie was the daughter of Louis VII of France and of Eleanor of Aquitaine. Both Marie and her mother and daughter were believers in the "Courts of Love", and which stated that love between husband and wife was impossible. Guenevere needed therefore a lover; and one had to be found for her. Lancelot was pressed into the role. Mordred, Guinevere's earlier lover, was too unsympathetic a character.
Nowhere do we find Lancelot and Guinevere as lovers before the Chevalier de la Charrette. Yet Chrétien does not claim to have invented the story. Walter Map, the chancellor of Henry II, may have been the original author of a Lancelot romance, which then formed the basis for the source of the German Lanzelet. The author of the Germen Lanzelet, Ulrich von Zatzikhoven, says that he translated his poem from a French book in the possession of Hugo de Morville, one of the English hostages, who, in 1194, replaced Richard Coeur de Lion in the prison of Leopold V of Austria.
Then in the Perlesvaus, the earliest French prose containing Arthurian romance, Lancelot's love affair with Guenevere re-emerges and Lancelot plays a part in the Grail quest almost equal to that of Perceval the hero and Gawain. Lancelot in this romance never sees the Grail.