Portolan charts are the first truly realistic maps that mankind ever created. They appeared in the 13th century, when the previous century’s renaissance in Mediterranean maritime trade meant that vast amounts of geographic information on the Mediterranean basin had been gathered. Initially, this information was collated in the form of portolans or lists of the estimated distances according to directions set by the compass, along with comments on the nautical advantages and hazards of some of the places mentioned. The shift from all this textual information to the graphic form of an accurate map is one of the great cultural revolutions in world history. Despite the fact that they were conceived as an instrument of navigation, their dissemination ended up radically changing the way medieval societies perceived and managed space, thus laying the foundations for the great Age of Discovery.
We can easily differentiate portolan charts from other ancient maps because they were always drawn under a characteristic tricoloured web of lines that represented the 32 winds or directions show by Late Medieval compasses. It is underneath this network of black, red and green lines that we find a cartographic design that is easily recognisable by its realism and always surrounded by a dense list of coastal place names penned on a perpendicular angle to the coastline. Generally speaking, these charts were made by specialist workshops that tended to be concentrated either in the great Maritime Republics of Genoa and Venice or in the city of Majorca, the epicentre of seafaring in the Crown of Aragon. From these three locations, thousands of sea charts were produced, sold and exported to places as far away as Flanders or Alexandria from the last third of the 13th century to the end of the 15th century. But only 180 examples have survived, and many of them are only fragments.
The portolan chart kept at the ACA is complete and surprisingly well preserved. It is one of only four medieval portolan charts that are kept in Spain. However, it is not a Majorcan chart, but an Italic one. It was incorporated into the ACA’s collections in the 1920s and its exact place of origin is not known, even though it has been repeatedly said, with no basis whatsoever, that it comes from the Convent of La Merced in Barcelona. It includes the archetypal web of 32 winds drawn over two concealed parallel circles. In terms of place names and mapping, it is a very unusual piece. It combines the standard Genoese elements of the time with others that are typical of the Venetian form and the phonetics of the place names do not quite match either the features of the Genoese dialect or the Venetian one. It is also surprising that its representation of the Atlantic coast has been made on a smaller scale than that of the Mediterranean coast, thus continuing the traditional errors of maps of the previous century.
ACA, Colecciones, Mapas y Planos, no. 1
Portolan chart (Mediterranean, Black Sea, Sea of Azov and North-East Atlantic) Salto de línea Anonymous Italic cartographer, 2nd quarter of the 15th Century Salto de línea Parchment, 419 x 849 mm Salto de línea Scale: 0.9cm for 50 nautical miles (1:7.000.000)