Medieval navigators’ charts also influenced Leardo. Towards the close of the thirteenth century sailors in the Mediterranean—particularly Italians and Catalans—began making marine maps (known as portolan charts) that far surpassed all earlier maps in the accurate delineation of coast lines. The majority of these show the Mediterranean and Atlantic coasts of Europe and of north Africa but little of the interior of the continents and nothing of the farther parts of Asia. Some, however, were used as the basis for maps of the world. On the latter the shore lines were derived from the navigators’ charts, and the remaining regions were compiled from other sources. The Leardo map belongs in this category. Among the existing maps dating from the fourteenth and early fifteenth centuries our Leardo map is very closely related to the group of maps drawn by the famous Catalan cartographers of Majorca in the Balearic Islands. In its general outlines it is so strikingly like a Catalan map of about 1450 now preserved in the Este Library at Modena[18] that we must assume a common cartographic ancestor at no great distance back. There are, however, certain legends on the Este map that Leardo does not give, particularly the long inscriptions and a multitude of place names on the Mediterranean and Atlantic coasts. Leardo’s map, on the other hand, has features not shown on the Este map. These are of two sorts: (1) place names in Asia and Africa, the counterparts of which may be found on other Catalan[19] and Italian[20] maps of the period; and (2) river, mountain, and province names taken directly from Ptolemy. There are also not a few names whose origins or counterparts on other maps I have been unable to trace. Ptolemy’s _Geography_ had been neglected during the earlier Middle Ages, but the enthusiastic interest in Greek literature which characterized the early Renaissance had led to its translation into Latin shortly before Leardo’s time.[21] A strict interpretation of Ptolemy’s data would have necessitated a complete redrafting of the outlines of the continents, as was done on the Ptolemaic atlases of the mid- and late fifteenth century. Leardo made no such attempt. The extent of his concession to the Ptolemaic geography was to sprinkle a few of Ptolemy’s names over a medieval base and to add the Rivers Indus and Oechardes in eastern Asia.[22] The Known World According to Leardo The numbers in parentheses correspond to the reference numbers in the Appendix (pp. 32-60) and on the key maps at the end of the book. In the Appendix (pp. 31-67) I have tried to identify as many as possible of the names and other features shown on the Leardo map with existing places, or at least with corresponding features on other maps of the period. Here I propose to conduct the reader on a rapid sight-seeing tour around the map, pointing out some of the most interesting details only. Asia