Dioneta is the name given to a sister of Gwyar (= Morcades) and to a sister of Gwalchmei (= Gawain) in the 14th cenury fragmentary Welsh text known as The Birth of Arthur, from Llanstephan MS 201, edited and translated by J. H. Davis in Y Cymmrodor Vol. 24 (1900), pp. 249–264. The Welsh passage in which the name appears runs: The English translation runs: The English translation with the proper names normalized is: