Afallach: av-AHL-akh
Welsh, from "afal"--apple: The One of Apples.

King of the isle which bears his name--Afallach, Latinized as "Avallo" and "Avalania" which has since been Angliziced as "Avalon". He is one of the kings of the Otherworld; in some literature, he is replaced by his nephew Gwyn ap Nudd as king of Avalon, which is identified with Glastonbury Tor¹. His daughter is usually listed as Modron, mother of Mabon ap Modron.²

Afallach is listed in the genealogies as the son of Beli and Anna, and ancestor to the royal houses of the Britons; as father of Modron, he would also be ancestor to Owain ap Urien.

As king of Avalon, he appears in the Lancelot-Grail cycle and Malory's Le Morte d'Arthur as Evelake/Mordrains, king of Sarras who would live from the time of Christ until the coming of the Grail Knights to release him from this existence. He is a double of the Fisher King.

NOTES
1. The first occurence seems to be in the text The High History of the Holy Grail (ca. 1220?), in which Avalon is implicitly identified with the monestary at Glastonbury.

2. Modron is in later texts said to be the wife of Urien Rheged, later romanticized as Uriens of Gorre, Gorre sometimes identified with Glastonbury. In later texts, the wife of Uriens is Morgan le Fay, which leads to the conclusion that Morgan le Fay, half-sister of Arthur, is a euhemerized goddess, Modron, daughter of the King of Avalon, and hense she is also the Lady of the Lake.