Arthurian legend is based, in part, on the mythological cycle featuring the Goddess as mother and the God as lover and son. Which make the characters in Arthurian legend gods and goddesses in their own right. Starting with the goddess archetypes, the main feminine characters in the legend are Guinevere, Igraine, and Morgan Le Fay. These women are the three aspects of the Triple Goddess; the Maiden, the Mother, and the Crone.
Guinevere is the Maiden aspect of the tripartite. She is the bride of King Arthur and lover of Lancelot, the Sovereign Queen of Britain, and the Queen of the May. She is associated with Beltane – the beginning of summer. As Queen of the Summer County this makes her also Queen of the Faery, which would equate her with Morgan Le Fay.
Igraine is the Mother aspect of the tripartite. She is the mother of King Arthur, the mother and sister of Morgan Le Fay (attributed to two separate people who are the same), the wife of Gorlois and lover of Uther Pendragon, and was once Queen of Britain. The similarities between her and Guinevere continue the ever-flowing cycle of the seasons.
Morgan Le Fay is the most complex aspect of the tripartite goddess, the Crone. In many versions of the legend, Morgan Le Fay is the same person as the Lady of the Lake and the High Priestess of Avalon. Avalon is similar to many Holy Isles or Lands of Faery as they also double as the Land of the Dead. Morgan le Fay is the sister and lover of King Arthur, and the mother of his son Mordred. She is the Mistress of Magic, and the nemesis of Merlin.