is derived from the attributed arms of Leofric, Earl of Mercia in the 11th century. It is worth noting, however, that Leofric is sometimes attributed a black, single-headed eagle instead. The wyvern, a type of dragon, came to have a strong association with Mercia in the 19th century. The Midland Railway, which used a white (silver) wyvern sans legs (legless) as its crest, having inherited it from the Leicester and Swannington Railway, asserted that the "wyvern was the standard of the Kingdom of Mercia", and that it was "a quartering in the town arms of Leicester". The symbol appeared on numerous stations and other company buildings in the region, and was worn as a silver badge by all uniformed employees. However, in 1897 the Railway Magazine noted that there appeared "to be no foundation that the wyvern was associated with the Kingdom of Mercia". It has been associated with Leicester since the time of Thomas, 2nd Earl of Lancaster and Leicester (c. 1278–1322), the most powerful lord in the Midlands, who used it as his personal crest, and was recorded in a heraldic visitation of the town in 1619. In Bram Stoker's 1911 novel The Lair of the White Worm, explicitly set in Mercia (see above), the Mercian white wyvern sans legs of the Midland Railway was transformed into a monstrous beast, the eponymous worm of the title. The word "worm" is derived from Old English wyrm and originally referred to a dragon or serpent. "Wyvern" derives from Old Saxon wivere, also meaning serpent, and is etymologically related to viper. The ultimate source for the symbolism of white dragons in England would appear to be Geoffrey of Monmouth's fictional work, The History of the Kings of Britain (c. 1136), which recounts an incident in the life of Merlin where a red dragon is seen fighting a white dragon and prevailing. The red dragon was taken to represent the Welsh and their eventual victory over the Anglo-Saxon invaders, symbolised by the white dragon. The philologist and Tolkien scholar Tom Shippey has suggested that the Middle Kingdom in J. R. R. Tolkien's Farmer Giles of Ham, a story dominated by a dragon, is based on Mercia, the part of England where Tolkien grew up. This dragon, Chrysophylax, though mostly hostile, eventually helps Giles found a realm of his own, the Little Kingdom. Shippey states further that "the Mark", the land of the