1 Accepted manuscript of the article published in Terrae Incognitae 49:1 (2017): 48-68: https://www.tandfonline.com/doi/full/10.1080/00822884.2017.1295600 The planisphere of Juan de la Cosa (1500): The first Padrón Real or the last of its kind? JOAQUIM ALVES GASPAR Principal Investigator of ERC Project Medea-Chart Faculdade de Ciências, Universidade de Lisboa, Portugal The chart drawn by Juan de la Cosa in 1500 is the earliest nautical planisphere of the early modern period that survived to the present day. On it, the world is depicted as it became known by the European in the end of the fifteenth century, after the great mari- time explorations to the New World, Africa and India. Apparently the cartographic standard adopted in the representation is the portolan chart model, with rhumbs radiat- ing from the compass roses and the geographic names written perpendicularly to the shorelines. However an important innovation distinguishes this planisphere from the other nautical charts produced by the cartographic workshops of the Mediterranean, which is the depiction of the Equator and the Tropic of Cancer. Not only these lines are placed in their approximately correct locations but also the module of 17 ½ leagues per degree of latitude, which became a de-facto standard in the Iberian nautical cartography throughout the sixteenth century, can be deduced from the spacing between them. This is a sign that astronomically-observed latitudes may have been incorporated into the representation. If that were indeed the case, the planisphere of Juan de la Cosa would be the earliest extant example of the so-called latitude chart, the new cartographic model that developed in the end of the fifteenth century, following the introduction of astro- nomical navigation. In order to investigate such possibility the results of a cartometric analysis focused on the representation of the Atlantic and Indian Ocean coastlines are presented and discussed. It is concluded that, like other contemporary nautical charts, the planisphere of Juan de la Cosa is a compilation of geographic information collected from different sources of different times. Contradicting previous studies, the chart ap- pears to have been constructed on the basis of magnetic courses and estimated distances between places. A punctual exception is the depiction of the Caribbean Sea and northern coast of South America, in which latitudes determined by Columbus in Cuba, and in the northern coast of South America, by Pinzón, may have played an important role. This interpretation fully explains the exaggerated size of the region when compared with Europe and Africa. KEYWORDS: Planisphere of Juan de la Cosa (1500), cartometric analysis, portolan charts, latitude charts. Juan de la cosa la fizo en el puerto de S: mã en año de 1500 (Juan de la Cosa made it in the port of Santa Maria, in 1500), this is the inscription written near the left margin of the oldest extant nautical planisphere of the early modern period, documenting its au-