The most widely cited source for Sir Gowther is a late-twelfth or early-thirteenth century romance of a fictitious Norman duke named Robert de Diable, a story probably taken from legend.[12][13] Influences may also be found in the saintly Legend of Gregorius and the Life of Saint Alexius.[14] At one time, the lai was believed to have come from Normandy, but a study published in the 1960s suggests that the fairy tale elements make historical inspiration unlikely and that the tale may have arisen in Italy.[15]
The visit of an other-worldly creature in an orchard, promising a marvelous child, parallels the legends of St. Anne and the birth of the Virgin Mary so closely that there would appear to be influence, especially as these are the closest parallels to be found.[16]
Unsurprisingly, resonances exist in other Breton lais, in particular the twelfth- or thirteenth-century lai Tydorel, which may itself derive from Robert de Diable,[17][18] The Middle English Breton lai Sir Orfeo also sees the heroine accosted by an Otherworldly figure in an orchard and the Middle English Breton lai Sir Degaré has the hero conceived when his mother is raped in a forest by an Otherworldly knight. The heroine of the Middle English Breton lai Emaré has to suffer a new life in reduced circumstances before gaining acknowledgement of her previous rank.
The late-twelfth century Anglo-Norman romance Ipomedon has the hero fight as an unknown knight on three successive days of a tournament, first as a white knight, then as a red knight and finally as a black knight, in a reversal of an otherwise identical sequence later used by the anonymous author of Sir Gowther. Indeed, the tournament where the hero fights in disguise and claims to have been busy is a fairy tale commonplace (such as in The Golden Crab or The Magician's Horse, or in Little Johnny Sheep-Dung and The Hairy Man, where it is actual battle), and from there passed into romance.[19]
