he is visited by the emperor . The board of is named as one of the Thirteen Treasures of the Island of Britain in lists dating from the 15th and 16th centuries; according to the lists the board is gold and the men silver, and the pieces play against each other automatically. A magic comparable to 's appears in the Arthurian romance Peredur son of Efrawg; a number of French versions of the Holy Grail story feature similar chessboards with self-moving pieces, following the Second Continuation of 's Perceval, the Story of the Grail, though in these only one side moves, while the hero plays the other. According to H.J.R. Murray's A History of Chess, the ultimate fate of Fidchell is shown a margin note upon one 15th-century manuscript about the Second Battle of Magh Tuireadh between the Tuatha Dé Danann and the Fomorians in Irish mythology. In the gloss, it is disputed whether Fidchell ("chess") could have been invented during the Trojan War, as both wars were traditionally believed to have taken place at roughly the same time and the Irish mythology manuscript refers to the playing of fidchell. While it is no longer possible to know whether it was introduced into Gaelic Ireland by the Hiberno-Norse or the Normans, by the 15th-century "Fidchell" had come to mean Chess in the Irish language and the original rules of the game had been completely forgotten. Confusion with tafl In the board games literature, it has often been suggested that is a variant of the Welsh game , itself descended from the Norse games. These games, along with the Irish , are played on a grid, often seven squares by seven, with the king in the middle. The king has a number of defending pieces around it at the beginning of the game, and they are surrounded by twice as many attackers. The object is to make a clear path for the king to the edge of the board, while the attackers must attempt to surround, and thereby capture, the king. However, variants are usually played with unequal numbers of pieces, the attackers being twice as numerous as the defenders. by contrast was played with equal numbers on both sides and there is no indication of a king piece. An artefact found in Ballinderry, County Westmeath in 1932, known as the Ballinderry Game Board, has been suggested to represent fidchell. This