Gwenhwyfach was a sister of Gwenhwyfar in medieval Welsh Arthurian legend. The tradition surrounding her is preserved in fragmentary form in two Welsh Triads and the Mabinogi tale of Culhwch and Olwen
"How King Artus slept each day with the Lady of Camelide and promised to marry her." An illustration from Lancelot en prose (c. 1494)