Portolan charts are medieval nautical maps, enriched with a wealth of geographical coastal names, conceived for being used by seafarers. Due to the fact that they used to be frequently rolled up and constantly consulted aboard, the surviving ‘carte da navigar’ are extremely rare and not always in good condition.
Portolan C.G.A.5.d (Majorca, 1450 ca.) 59 × 76 cm, shows the whole the Mediterranean basin, the coasts of the Atlantic – from the British isles to Cape Bojador in Africa –, a part of Central Europe and the territories of North Africa. European places reproduced on this map are the Alps, with their Tshape, the Pyrenees, the cities of Venice, Genua, Prague, Granada and Santiago de Compostela, the Balearic Islands. In Africa the mountains of the Atlas stand out, whereas the caption near the Red Sea recalls Hebrews' crossing during the flight from Egypt.
Portolan C.G.A.5.b (Majorca, 1450-1460 ca.), 61 × 90 cm, shows the Mediterranean basin and the Atlantic from Norway to Morocco. Less decorated than the previous one, it is likely to have been a real ‘carta da navigar’ to be used on board by seamen. The cities of Barcelona, Valencia, Santiago de Compostela, Granada, Venice and Genua are singled out. Just a few natural elements are used, whereas symbols of human presence – such as flags, shields and towns – are more common.
Portolan C.G.A.5.c is the most ancient document of Portuguese nautical cartography. Anonymous and trimmed to 60 x 73 cm, it shows the Portuguese discoveries of African coasts after the explorations of Fernando Gomes in 1471-72. The emphasis on Lisbon and Ceuta and all the flags pointing out landing-places on African coasts allowed scholars to date the map between 1472 and 1482.
This collection of three ancient portolans, belonging to the Biblioteca Estense, is presented in a walnut showcase, sized 67 × 45 × 14 cm together with the commentary, the certificate of authenticity, a wooden-bronze paperweight and a valuable magnifying lens. Each map can be purchased separately, presented in a tube.