Text Category: Miscellaneous, Continental and English Arthurian Texts
Cornish
Merlin the Diviner
French and Anglo-Norman Arthurian Texts
Anonymous
The Lai of Tyolet
The Knight of the Two Swords
The High History of the Holy Grail
The Quest for the Grail
Robert de Boron
The Modena Manuscript: from the Le Roman du Graal, translated by Dell Skeels:
Perceval
Mort Artu
Chretien de Troyes
Cliges
Erec et Enide
Lancelot, or, the Knight of the Cart
Yvain, or, the Knight With the Lion
Though there is no complete online version of Perceval, or, the Story of the Grail, Kirk McElhearn has begun to work on a translation on the web, which can be found here. Meanwhile,
the following are from the continuations of the romance of Perceval, left unfinished by Chretien de Troyes:
The Elucidation: the Pseudo-Chretien prologue
Sir Gawain and the Lady of Lys: from the Perceval Continuation One
Sir Gawain at the Grail Castle: also from the Perceval Continuation One.
Marie de France:
Lais (But especially see those below)
Lanval
Chevrefoil (a version of Tristan and Iseult)
Wace:
Arthurian portions of The Brut
German Texts:
Anonymous
Diu Krône: The Crown (Gawain and the Grail) [Selections from the text, translated by Jessie L. Weston]
Wolfram von Eschenbach:
Parzival
English Texts:
Anonymous
The Adventures of Arthur at the Tarn Wadeling
Sir Cleges
Sir Gawain and the Green Knight
Sir Libeaus Desconus
La3amon
Arthurian portions of The Brut
Brut (Cotton Caligula version)
Brut (MS Cotton Otho version)
Thomas Chestre
Sir Launfal
The Camelot Project
This website collects a large number of Middle English texts dealing with King Arthur; instead of listing the entire contents (which is quite large), simply go there and see for yourself.