Gauvain, hero of a mediæval French romance, Le Chevalier à l' Epéc, erroneously attributed to Chrestien de Troyes.  Gauvain is received in a splendid castle, after having been warned by a friendly peasant that no one may find fault at aught within, under pain of death.  So he abstains from criticism.  He had not been forewarned of a second rule, that any one who attempted liberties with the chatelain's daughter would instantly be decapitated by a magic sword.  On the second night he is locked in the same room with that damsel.  She takes a liking to him and reveals everything.  Subsequently he marries her.  She reappears in the metrical romance of Perceval.  She there runs away with a lover, taking Gauvain's greyhounds with her.  Gauvain catches up with the fugitives.  He leaves to his wife the choice of returning or continuing her flight.  She elects to throw in her lot with her lover.  When the same choice is offered to the greyhounds they remain with their master.  This last story, with other women for its heroines, reappears in many French and English romances. (Heroes and Heroines of Fiction, &c., Walsh, 1915)