Note that medieval manuscripts often distinguish minimally among letters formed of one, two, or three short strokes: minimum consists of 15 short strokes but nimium has only 12, and that's how you can tell them apart.... So Gue + 8 strokes + ar = Guennuuar or else it = Guennimar, depending on who is reading it. The letter "u" can represent a vowel or a "v" sound.
Gwenhwyfar. Variants found in various mss: Gwenhvyfar, Gwenhvyuar, Guenhvyuar; Gwennhwyuar, Gwennhwyvar, Gwenhwyvar, Gvenhvyuar, Gvenhyuar, Gwenwyvar. The first syllable can also be spelled Wen- or Uen-, representing a loss of the initial /g/ sound in certain syntactic situations. (--thanks to John Bollard)
Presumed to come from Brittonic *Uendu-sebara (Pale/fair phantom/fairy) > Archaic Welsh *Uennhebar > Old Welsh * Guennhuibar > Guenhuiuar. Known as Arthur's wife in Culhwch & Olwen, the Triads, the Melwas Dialogue, and the Welsh Brut. (--thanks to Chris Gwinn)
An alternative etymology: Gwenhwy + fawr [< mawr 'great'] in contrast with Gwenhwy + fach [< bach 'small'], i.e. Gwenhwy the Great(er) and her sister Gwenhwy the Less(er), so to speak. Both of them are named in 'How Culhwch Got Olwen' and 'Trioedd Ynys Prydein'. See Bromwich's Trioedd Ynys Prydein, s.v. Gvenhvyuar (uerch Ogvran Gavr). (--thanks to John Bollard)
Vita Gildae (Caradoc of Llanfarcan, ca. 1130): She is mentioned by name once and it is spelled: "Guennuuar" (Guennuvar) in one manuscript (Burney 310, British Museum); "Guennimar" in another (Cambridge Corpus Christi 139); see Monumenta Germania Historica III, ed. Mommsen, for both readings. Her character is that of a queen who is abducted and raped (violatam et raptam) by Melwas, king of the summer region, and held by him in Glastonbury while Arthur seeks her; Arthur eventually recovers her with the help of the abbot of Glastonbury and St. Gildas.
Geoffrey of Monmouth, Historia Regum Britaniae (ca. 1138): She is mentioned four times and the most common spelling in all mss. is Ganhumara though many or all mss. spell it in the first mention with the first syllable as Gwen- or Guen-. The first syllable can also be spelled Gun, Gwn, or Wn.. The rest of the name can be spelled -humera, -heuara, -hauera, -heuera, huaura, -wara, -hwara, -iura -nuera (--thanks to Chris Gwinn) . She is of noble roman parentage. Geoffrey does not discuss whether or not she loved/colluded with Mordred in taking over Arthur's realm in his absence.
Gerald of Wales: Wenneuereia (citing the inscription on the cross dug up at Glastonbury in 1191--thanks to Chris Gwinn).
Wace, Roman de Brut (ca. 1150-55;MS. K). She is named twice. Arthur marries Genoivre (= Juniper) and turns over the realm to "Gahunmare sa femme" and Modret when he leaves for the continent. Modret is already in love with his aunt, and she does love him and collude with him to take over the kingdom in Arthur's absence.
Marie de France presents the character of Arthur's Queen in Lanval but does not name her. She lusts after a young knight but is foiled..
Beroul, Tristan. Arthur is seen holding court in two different places but does not appear to be married. (In the Tristan of Thomas Arthur is mentioned but not in a context in which Guinevere would be likely to appear.)
Berne Folie Tristan: Guenievre Arthur's wife is mentioned as the object of the love of "Yder who killed the bear." The triangle is compared to that of Mark, Iseut, and Tristan.
Chretien de Troyes (ca. 1170-90): Guenievre or Ganievre (6x in Erec et Enide, 2x in Chev. de la Charrette, once only (late) in Yvain). She appears also in the Conte du Graal and Cligés without being named. She is active in Arthur's court and promotes young lovers in two of the romances. She is very comfortable and confident with Arthur's knights (e.g. beginning of Yvain). She is vulnerable to insult in the Graal. In the Charrette, she is handed over on a pretense to Meleagant, who takes her to Gorre; she is rescured by Lancelot, with whom she commits adultery. Lancelot is however able to defend her from charges of adultery with Kay, when she is so accused.
The Charrette project (online critical edition of Chretien's Chevalier de la Charrette) and the associated Figura database allow a quick comparison of the various spellings in the two occurrences (lines 1111 and 3220 in their numbering) of the name in 6 different MSS. The spellings Guenievre (guenieure) and Ganievre (ganieure) are editors' versions of the spelling found in MS. C, the Guiot copy, which is the basis of most editions of Chretien's romances. Other MSS read geniure and jenoiura (A); geniure and geniur (E); ienieure (G, missing the second passage)); ganieure twice (T); genieure and geniure (V).
Layamon's Brut (early 1200s): MS Cotton Caligula usually has Wenhauer; also Wenhæuere 11103 Wenhaiuer 11320 Wenhæiuer 12235 (Note: other names beginning in Guen-are spelled with Guen-).. MS Cotton Otho has Gwenayfer. Same story as Wace, above, with even more emphasis on her love of Modret and collusion with him. In most of the chronicles listed below, the queen is mentioned by name 3 times: once at her marriage, once when Arthur leaves Britain in response to Lucius's challenge, and once when she learns that Mordred is being defeated by Arthur, and she decides to retire to a nunnery.
Robert of Gloucester, Metrical chroncle (1260-1300) : Gwenwar, Gwenwayr (ms. variants gueniuar, guenhuuer,gouernewaur, gwenheouer, Gwennoure, Gwennore, Gwenuar, gwenheouer)
Robert Mannyng, Story of England (1288-1338): Guenneuera (Latin rubric), Genoyre; Guenore (Lat & English)
Brut (prose, Ms. Raw. B171, Bodleian Library, ca. 1350): Gunnore, Gunore. She is Cador's cousin. She and Arthur have no children. She is passive with respect to Mordred but knows that she has shamed Arthur.
Ralph Higden's Polychronicon, trans. John Trevisa et al (?): Gwenvere (other mss: Guennevere, Gwenner), Guenera. References to the grave of Arthur in Glastonbury.
Stanzaic Morte Arthur (1300s) : Genure , Gaynour, Gaynor. Follows the Old French story about the love of Guinevere and Lancelot.
Sir Gawain and the Green Knight (1300s): Guenore, Gaynour. A courtly queen, object of the anger of Morgan.
Alliterative Morte Arthur : Waynour, Waynore, Waynor (once at beginning of a line, otherwise in middle of line, always in allteration); Gaynour (twice, once at beginning of line and once as a form of address, both in alliteration). The Queen is handed over to Mordred when Arthur leaves for the continent, and later he hears Mordred has married her. She has children and is not admirable at the end.
Awntyrs off Arthure at the Terne Wathelyne (2 different mss; Scottish alliterative poem): Waynour, Gaynour, Gaynor (we also have both Gawayne and Wawayne). Both forms alliterate so probably the distribution of initial w/g is stable..
Lydgate, Reason and Sensuality, Guenore. She is mentioned as having played chess with Lancelot.
Merlin (mid 15th-c.). Gonnore, Gonnere. This includes the story of the 2 Gonnores....
Malory (Caxton): Gueneuer, Gweneuer, possibly others.
Ginover, Ginovere (Hartmann, Wolfram, Ulrik). Ulrik in the Lanzelet tells how she is the object of desire of King Valerin, who takes her to his castle and puts her into a sleep; eventually Arthur, with the help of his knights and the sorcerer Malduc, frees her.