The Leardo Map of the World, 1452 or 1453 / In the Collections of the American Geographical Society

by John Kirtland Wright

Sources of Leardo’s Geography

Briefly stated, the sources of Leardo’s geography are to be sought in the information accumulated by the Greeks and Romans, as added to and altered during the early Middle Ages by the Church Fathers on the basis of the interpretation of the Bible and as later augmented by the work of medieval travelers, merchants, and sailors.

At a very early period the Greeks developed the idea (borrowed, perhaps, from the Babylonians[16]) that the earth is a flat disk surrounded by the Ocean Stream. This conception seems to have given rise to a cartographic tradition followed by certain ancient and medieval map-makers who had long outgrown the belief that the earth is actually flat. Thus Leardo draws a circular land mass, or oikoumene, surrounded by a narrow hem of water. We cannot, however, question his belief in the sphericity of the earth, for otherwise he could hardly have held the views expressed in the panel below the calendar. Furthermore, his two legends relating to the fiery and frozen deserts echo a theory that was propounded in classical times and based on the hypothesis of a spherical earth. This theory, worked out in detail by Crates of Mallos, is briefly as follows.[17] Around the equatorial circumference of the globe is a fiery zone so intensely hot that no man can cross it. This zone cuts off all communication with the southern hemisphere. The north and south polar caps are uninhabitable because of the cold. An ocean encircling the globe from north to south intercepts communication with the half of the northern hemisphere opposite the oikoumene. Many maps were made in the Middle Ages to illustrate this conception. Leardo presumably had it in mind and did not intend to represent either a flat disk or a complete hemisphere but merely a circular portion of the earth’s surface lying north of the equator.

In its orientation, with east and the Terrestrial Paradise at the top and with Jerusalem at the center, the map follows the Christian tradition of the earlier Middle Ages. Other features reflecting the influence of the Scriptures are Noah’s Ark resting on top of Mt. Ararat, Mt. Sinai, the exaggerated length of the River Jordan, and an inscription in the far northeast referring to Gog and Magog.

Later medieval contacts between Europe and remote lands are revealed in names derived from Marco Polo and possibly from other Western travelers who had visited the Orient, as well as in the Arabic names in Asia and Africa.

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]