Gwenhwyfach (Middle Welsh:Gwenhwyvach,Middle Welsh:Gwenhwywach, orMiddle Welsh:Gwenhwyach; sometimesanglicized toGuinevak) was a sister ofGwenhwyfar (Guinevere) inmedieval WelshArthurian legend. The tradition surrounding her is preserved in fragmentary form in twoWelsh Triads and theMabinogi tale ofCulhwch and Olwen.
This relatively obscure figure is first mentioned inCulhwch and Olwen, where her name (spelledGwenhwyach) is among those 200 men, women, dogs, and horses invoked by the heroCulhwch to punctuate his request thatKing Arthur help him find his loveOlwen. Both of the Triads that mention Gwenhwyfach refer to the enmity between her and her sister that led to theBattle of Camlann. Triad 53 lists as one of the "Three Harmful Blows of the Island of Britain" the slap that Gwenhwyvach gave her sister that caused the Strife of Camlann. Identifying Camlann as one of Britain's "Three Futile Battles",Triad 84 mentions it was started because of a dispute between the sisters. Some have suggested that "Gwenhwyfach" in Triad 53 is a mistake for "Medrawd" (Mordred), since Triad 54 describes Medrawd raiding Arthur's court and throwing Gwenhwyfar to the ground and beating her; this interpretation does not explain Triad 84, however.
Rachel Bromwich notes, citing the spelling found inCulhwch and Olwen and Triad 84, thatGwenhwyach may in fact be the original spelling of the name.[1] Melville Richards and Bromwich previously suggested that the alternate spelling of her name in medieval Welsh sources, Gwenhwywach, could have been understood asGwenhwy-fach, or "Gwenhwy the Lesser", aback-formation based on afalse etymology of her sister's name asGwenhwy-fawr, meaning "Gwenhwy the Great".[2][3] It is possible that Gwenhwyfach was once thought of as a darker aspect of Gwenhwyfar.[4]
TheLancelot-Grail cycle introduced a possibly related character known as "the False Guinevere" or "Guinevere the False". She is the real Guinevere's namesake identical but evil half-sister by a different mother. Also known as the Lady of Camelide (Dame de Camelide), she bewitches Arthur and turns him against the real Guinevere. She later dies of disease, confessing on her deathbed. (In the non-cyclicalLancelot, she confesses and is then burned afterLancelot wins atrial by combat against her three champions.)
Some modern writers associate Gwenhwyfach with Mordred, presumably due to her association with Camlann; she appears as the traitor's wife inThomas Love Peacock's novelThe Misfortunes of Elphin (1829), for example. InBernard Cornwell'sEnemy of God (1996), she is Guinevere's delusional and dim-witted fat sister who aids Arthur in his supposed "rescue" of Guinevere from Lancelot's castle and later becomes completely insane while living all alone.
According toPatrick Sims-Williams, in Welsh the "termination of -ach evokes unpleasantness" (Sims-Williams 1991:42). Therefore, Gwenhwyfar's sister Gwenhwyfach, found in the Welsh triads (Bromwich 1978) andCulhwch and Olwen (Ford 1977:131), may represent an unpleasant or evil form of Gwenhwyfar herself.