Arthur's magic possessions form a prominent element in Welsh tradition, and their appearance in the early chronicles is an important testimony to the diffusion of Welsh legend. _Kilhwch and Olwen_ contains a list of his belongings, all of which there is reason to believe, from record or from logical inference, were of otherworld origin. Each has its significant proper name, which in most cases conveys the idea of brilliant whiteness, a characteristic of Celtic fairy objects. His ship, for example, is named White Form, his shield "Night Gainsayer," his dagger "White Haft." The _Dream of Rhonabwy_ [20] describes his carpet (or mantle), "White," which had the property of retaining no colour but its own, and of making whoever was on it (or wrapped in it) invisible, and also his sword, "Hard-breacher," graven with two serpents from whose jaws two flames of fire seemed to burst when it was unsheathed, "and then so wonderful was the sword that it was hard for any one to look upon it." This sword (Caletvwlch, Caliburn, Excalibur) is a Pan-Celtic marvellous object, and is one of Arthur's most famous possessions. The deadly blows attributed by Nennius to him in the Battle of Mount Badon without doubt traditionally were dealt by Caliburn. Geoffrey of Monmouth recognised it as a fairy sword, and says that it was made in Avalon, namely, the Celtic otherworld. We may also feel confident that the full panoply of armour with which Geoffrey equips Arthur (ix. 4) consisted of magic objects, although Geoffrey, who in general, as an historian, rationalises the supernatural, merely describes them as amazingly efficacious. The shield he calls by the name of Arthur's ship in Welsh sources, Pridwen (evidently a fairy boat, limitless in capacity), either from some confusion in tradition, or because, being enchanted, Pridwen might, of course, serve as either ship or shield. Layamon adds further information about Arthur's weapons. His burny, he says (vs. 21133-34) "was named Wygar" (Anglo-Saxon _wigheard_), "Battle-hard," "which Witeze wrought," Witeze being a corrupted form for Widia, the Anglo-Saxon name of the son of Weland, the Teutonic Vulcan, a famous maker of magic weapons in romance, with whom his son might easily become identified in legend.