Early appearances of Morgan in Arthurian literature do not elaborate her character beyond her role as a goddess, a fay, a witch, or a sorceress, generally benevolent and connected to Arthur as his magical saviour and protector.

Her prominence increased as the legend of Arthur developed over time, as did her moral ambivalence, and in some texts there is an evolutionary transformation of her to an antagonist, particularly as portrayed in cyclical prose such as the Lancelot-Grail and the Post-Vulgate Cycle.

[19] A fictionalised version of the historical king Urien is usually Morgan le Fay's husband in the variations of Arthurian legend informed by continental romances, wherein their son is named Yvain.

[33] Morgen is also said to be a learned mathematician[34] and to have taught it and astronomy[35] to her fellow nymph (nymphae)[29] sisters, whose names are listed as Moronoe, Mazoe, Gliten, Glitonea, Gliton, Tyronoe, Thiten (Thitis), and Thiton (Thetis).

[10] As Orvan the Fairy (Orva la fée, likely a corruption of a spelling such as *Morgua[a] in the original-text),[39] there she first lustfully[40] loves the Trojan hero Hector and gifts him a wonderful horse, but then pursues him with hate after he rejects her.

[29] In the romance poem Lanzelet, translated by the end of the 12th century by Ulrich von Zatzikhoven from a now-lost French text, the infant Lancelot is spirited away by a water fairy (merfeine in Old High German) and raised in her paradise island country of Meidelant ('Land of Maidens').

[16] Guingamor's own lai links him to the beautiful magical entity known only as the "fairy mistress",[44] who was later identified by Thomas Chestre's Sir Launfal as Dame Tryamour, the daughter of the King of the Celtic Otherworld who shares many characteristics with Chrétien's Morgan.

[42] The Middle Welsh Arthurian tale Geraint son of Erbin, either based on Chrétien's Erec and Enide or derived from a common source, mentions King Arthur's chief physician named Morgan Tud.

[53] In the anonymous First Continuation of Chrétien's Perceval, the Story of the Grail, the fairy lover of its variant of Guigomar (here as Guingamuer) is named Brangepart, and the two have a son Brangemuer who became the king of an otherworldly isle "where no mortal lived".

[56] Speculatively, Loomis and John Matthews further identified other perceived avatars of Morgan as the "Besieged Lady" archetype in various early works associated with the Castle of Maidens motif, often appearing as (usually unnamed) wife of King Lot and mother of Gawain.

[b]) Integrating her figure fully into the Arthurian world, they also portray Morgan's ways and deeds as being much more sinister and aggressive than they are in Geoffrey or Chrétien, showing her undergoing a series of transformations in the process of becoming a much more chaotic and unpredictable character.

It was written c. 1200 by the French knight-poet Robert de Boron, who described her as an illegitimate daughter of Lady Igraine with an initially unnamed Duke of Tintagel, after whose death she is adopted by King Neutres of Garlot.

"[59] The Vulgate Suite du Merlin narration describes Morgan's unmatched beauty and her various skills and qualities of character: She was comely in body and features, she stood straight and was wonderfully pleasant and a good singer.

The most famous and important of these machinations is introduced in the Post-Vulgate Suite, where she arranges for her devoted lover Accolon to obtain the enchanted sword Excalibur as well as its protective scabbard, which has been previously confided to Morgan by Arthur himself as he had trusted her even more than his wife, replacing the real ones with fakes.

Confident of her coming victory, Morgan also attempts to murder her sleeping husband Urien with his own sword, but in this act she is stopped by their son Yvain (Uwayne), who pardons her when she protests she has been under the devil's power and promises to abandon her wicked ways.

Overjoyed with their reunion, the king allows Morgan to return to Camelot, but she refuses and declares her plan to move to the Isle of Avalon, "where the women live who know all the world's magic," so she can dwell there with these (unspecified) other sorceresses.

[97] However, disaster strikes Arthur when the sight of Lancelot's frescoes and Morgan's confession finally convinces him about the truth to the rumours of the two's secret love affair (about which he has been already warned by his nephew Agravain).

Malory also reused the magic mantle assassination plot from the Huth Merlin in a slightly modified form, resulting in Morgan's damsel instantly burnt to cinders by its curse when she is forced to take it on.

In one of later episodes, Morgan plots an elaborate ambush in "The Book of Sir Tristram de Lyons", after learning of the death of one of her favourites in a tournament, but Tristan ends up killing or routing thirty of her knights.

Unlike in the French and earlier stories on which Le Morte d'Arthur is based, and where Morgan and Arthur usually would either have first made peace or have just never fought to begin with, here her change of attitude towards him is sudden and unexplained (similar to the Post-Vulgate).

[110] Middle English romance Arthour and Merlin, written around 1270, casts a villainous Morgan in the role of the Lady of the Lake and gives her a brother named Morganor as an illegitimate son of King Urien; her wondrous castle Palaus is built mostly of crystal and glass.

Morgan's importance to this particular narrative has been disputed and called a deus ex machina[115] and simply an artistic device to further connect Gawain's episode to the Arthurian legend, but some regard her as a central character and the driving force of the plot.

In the case of Spain, even public edicts dating from the end of the 14th and the beginning of the 15th century tell of the belief in Morgan continuing to enchant and imprison people at Tintagel and in "the Valley of False Trickery".

[120] She arrives accompanied by two of her fay sisters named Arsile and Maglore to dispense enchantment gifts to and curses upon several characters including the author himself, and in the course of the story reverts her love interest in the local mortal (and unfaithful) knight Robert to her previous lover Hellequin (Hellekin), a demonic prince of Faerie who has been trying to woo her back.

Ever lascivious and sexual, Morgan lives in a splendid enchanted castle in the wilderness (identified as Brocéliande in a later manuscript) with twelve other beautiful fairy ladies including the sorceress Madoine.

In the 14th-century French Crusadic fantasy Le Bâtard de Bouillon, the island kingdom of Arthur and his fairy sister Morgan the Beautiful is hidden by a cloud in the Red Sea,[132] where it is visited by King Bauduins (Baldwin II of Jerusalem).

[144] In the 14th-century Ogier le Danois, a prose redaction of the epic poem Roman d'Ogier, Morgue la Fée lives in her palace in Avalon together with Arthur and Oberon, who both seem to be her brothers.

[148] In another French chanson de geste, the early-13th-century La Bataille Loquifer, the fays[29] Morgan (Morgue) and her sister Marsion (Marrion) bring the Saracen hero Renoart (Renouart, Rainouart) to Avalon, where Arthur is the king.

Meanwhile, the Fastnachtspiel (Ain Hupsches Vasnacht Spill von Künig Artus), a German retelling of the enchanted horn episode, moved Morgan's Mediterranean Sea island domain to the east of Sicily, referring to her only as the Queen of Cyprus.

In Matteo Maria Boiardo's late-15th-century Orlando Innamorato, fata Morgana (initially as lady Fortune[164]) is beautiful but wicked fairy enchantress, a sister of King Arthur and a pupil of Merlin.