THOUGH neither Shakespeare nor Wordsworth had the famous queen of faery, Morgain, in mind, the quotations may well illustrate the diversity of attitudes, from extreme repugnance to charmed wonder, which the medieval romancers exhibit in their descriptions of her person and their delineation of her character. Morgain may bLthe most beautiful of nine sister fays, or an ugly crone. She may be Arthur's tender nurse in the island valley of Avilion, or his treacherous foe. She may be a virgin, or a Venus of lust. In her infinite variety she enthralled the fancy of the Middle Ages, and has lived on to our day not only in literature but also in folklore. As the Fata Morgana, she still evokes the mirages in the Straits of Messina. Manifestly a creature of tradition rather than invention, she must have had a long and complicated history a history which has yet to be written. In the following pages I attempt a sketch of her genesis and evolution which seems justified by the evidence. Nothing could be more astonishingly elaborate, and, if true, more significant for the understanding of Arthurian romance. The mysteries of her complex character become clear, and much besides that is most perplexing in the Matiere de Bretagne. The fay makes her first appearance in literature as Morgen in a well known passage in Geoffrey of Monmouth's Vita Merlini (ca 1150).1 She is the fairest and the chief of nine enchantresses, skilled in flying swiftly through the air and in the art of healing. They dwell on an island of amazing fertility, which we easily recognize as the Isle of Avalon. For hither Arthur was brought to be healed after the battle of Camblan. This passage might seem the logical starting point for our inquiry, but though I shall refer to it frequently, I prefer to take up first the second appearance of Morgain in literature, a less familiar passage in the Roman de Troie, which Benoit de Ste.-Maure composed about 1160. In the excellent edition by Consta'ns, vss 8023-33, we are introduced to the steed of Hector of Trov.2