No such book can be found. It is probable that Geoffrey used Welsh and Breton traditions, and the patchwork book, parts of it very early, called the "History of the Britons," attributed to Nennius (about 796). In this we have a mixture of the real fighting Arthur of about 520, and the fabulous Arthur, a wonderful, powerful being, like all the old heroes of fable, who goes down to the mysterious land of darkness, like Odysseus and the Finnish Waïnamoïnen. The patchwork book of Nennius derives the name of Britain from that person of pure fantasy, "Brut," "Brutus," great-grandson of Æneas; who sailed to the Isle of Albion. Now "Brut" was invented merely to explain the name "Britain," and to connect the Britons, or Welsh, with the Trojans. In the same way the Scots had framed false histories of their ancestress Scota, who came from Scythia to Ireland, by way of Egypt, Athens, and Spain. All these legendary and fictitious materials, and others, were used by Geoffrey in what he called a "History"; and his "History," in spite of criticism, became the most popular book of the age. He begins with the flight of Æneas from Troy, and the flight of the great-grandson of Æneas, Brutus, to the Isle of Albion, "inhabited by none but a few giants". Brut builds New Troy (London) on the Thames, and so the romance runs on, a mere novel of adventures, those of Shakespeare's "King Lear" and "Cymbeline," for example, mixed up with history from Bede, till we come to Merlin the Enchanter, and Uther Pendragon, and the mysterious birth of Arthur, who is crowned king, and slays 900 Saxons with his own sword in one battle, conquers all Northern Europe and France, and defeats the Romans, all of which is sheer mediaeval fable. At home, in a great fight ("the battle of Camlan" it is called in older books than Geoffrey's) he kills Modred, and is carried to the Isle of Avallon or Avilion, to be healed of his wounds. Geoffrey ends by requesting historians, his contemporaries, such as William of Malmesbury, "to be silent concerning the "History of the Britons," since they have not that book written in the British tongue, which Walter, Archdeacon of Oxford, brought out of Brittany". This is mere open banter. Geoffrey was not likely to show them that book! Even in the old Welsh tale of the great boar-hunt, a story far earlier than Geoffrey's time, Arthur is surrounded by many fabulous heroes, really characters of fairy-tale, like them who followed Jason in the search for the Fleece of Gold. All of them can do miraculous feats, like the heroes of "the dream-time," "the dark backward" of unknown ages. These companions of Arthur become, at least some of them do, the Knights of the Round Table in the later romances, but we do not yet hear of Launcelot, or of the Holy Grail.