The better to establish his authority, Geoffrey himself had been careful to appeal to a mysterious source, a certain book of which no trace has ever been found, and which he pretends was given him by his friend Walter, Archdeacon of Oxford. Armed with this proof of authenticity, which no one could contest, he ends his history by a half-serious, half-joking challenge to the professional chroniclers of his time. "I forbid William of Malmesbury and Henry of Huntingdon to speak of the British kings, seeing that they have never had in their hands the book Walter, Archdeacon of Oxford, brought me from Brittany." Cervantes never spoke with more gravity of Cid Hamet-ben-Engeli. Such a book could not fail of success; it had a prodigious fame. Some historians lodged protests; they might as well have protested against Dares. Gerald de Barry cried out it was an imposture; and William of Newbury inveighed against the impudence of "a writer called Geoffrey," who had made "Arthur's little finger bigger than Alexander's back."[183] In vain; copies of the "Historia Regum" multiplied to such an extent that the British Museum alone now possesses thirty-four of them. The appointed chronicler of the Angevin kings, Wace, translated it into French about 1155, with the addition of several legends omitted by Geoffrey, that of the Round Table among others.[184] It was turned into Latin verse, into French alexandrines, into Welsh prose; no honour was denied it. From this time dates the literary fortune of Arthur, Merlin, Morgan the fairy, Percival, Tristan and Iseult, Lancelot and Guinevere, whose deeds and loves have been sung from century to century, down to the day of Shakespeare, of Swinburne, and Tennyson. The finest poems the Middle Ages devoted to them were written on English ground, and especially the most charming of all, dedicated to that Tristan,[185] whom Dante places by Helen of Troy in the group of lovers: "I beheld Helen, who caused such years of woe, and I saw great Achilles ... Paris and Tristan."[186] Tristan's youth was spent in a castle of Leonois, by the sea. One day a Norwegian vessel, laden with stuffs and with hunting-birds, brings to before the walls. Tristan comes to buy falcons; he lingers to play chess with the merchants; the anchor is weighed, and Tristan is borne off in the ship. A storm drives the vessel on the coast of Cornwall, and the youth is conducted before King Marc. Harpers were playing; Tristan remembers Briton lays; he takes the harp, and so sweet is his music that "many a courtier remains there, forgetting his very name."[187] Marc (who turns out to be his uncle) takes a fancy to him, and dubs him knight. "Should any one," says the author of one of the versions of Tristan, "inquire of me concerning the dress of the knights, I will tell him in a few words; it was composed of four stuffs: courage, richness, skill, and courtesy."