Anyone who has ever seen a late medieval mappamundi or portolan chart will be able to appreciate the sentiments of a Sicilian songster, captured in a mass-setting of the third quarter of the fifteenth century: enchanted by the beauty of the maps, he searched them for a lovelier isle than his own, albeit without success. 1 The finest surviving example of the cartography of the period, the 'Catalan Atlas' of the Bibliothèque Nationale, Paris, generally attributed to Cresques Abraham of Majorca, is as rich and intricate as a spilled jewel casket, resplendent with powerful images of exotic beings and untold wealth. 2 Maps of even greater magnificence, larger and more densely illuminated, are recorded but lost. 3 These were royal gifts, intended for ostentation as well as use, but the more modest and practical portolan charts would be drawn with grace and adorned with illustrations or, at least, with fine calligraphy and a delicate web of rhumb-lines. It was a period in which maps could inspire more than music. It was almost certainly a map - perhaps even the Catalan Atlas itself - that in 1402 induced the Poitevin adventurer, Gadifer de la Salle, to embark on a quest for the mythical 'river of gold' which led to his ruin. In the late fourteenth century, the anonymous author of the Libro del conoscimiento de todos los reynos constructed from the legends of maps a fantastic journey of the imagination which reached beyond the limits of the known, even of the accessible world. 4