This anonymous portolan chart is an interesting example of fifteenth-century nautical cartography. Although it is undated, it is believed to have been made around 1472, and is thus the oldest surviving Portuguese chart. Oriented to the north, the chart depicts the Atlantic coast from southern France to the Gulf of Guinea, as well as the Atlantic islands, such as the Canaries, Azores, Madeira, and Cape Verde. Several cities and flags are also portrayed, showing the presence of the Portuguese in Western Africa in the second half of the fifteenth century.
Although neither the author nor the date of creation of the chart is clear, it is a remarkable example of late medieval portolan charts, showing the Portuguese discoveries in western Africa during the last quarter of the fifteenth century.
A Reflection of Its Time
This chart is made on a single piece of parchment that measures 60 x 73 cm. It depicts the Atlantic coast from Normandy to the Gulf of Guinea, following the tradition of early nautical charts.
The place names, written in Portuguese, are abundant, and cover the whole coastline. The contrast between the coasts of the Iberian Peninsula, completely covered with toponyms, and those of northwestern Africa, with some blank spaces, indicates that knowledge and exploration of African coasts were still in progress.
We can see two scales of leagues at the left margin of the chart, as well as seven compass roses, one of them, more elaborate, located in northwestern Africa. Several Atlantic archipelagos are visible, such as the Azores, Madeira, the Canary Islands, and Cape Verde, which are colored in blue, red, and green.
As we can see in other nautical charts, the island of Lanzarote, in the Canaries, is marked by a red cross, perhaps indicating the Genoese flag, with reference to the voyage of the Genoese sailor Lancelotto Malocello, who was the first European to rediscover the island in the fourteenth century.
Both in Africa and Europe, several important cities are portrayed, and a series of flags indicate the Portuguese exploration of Africa during the third quarter of the fifteenth century. Thus, the chart is an interesting document that shows the Portuguese exploration of the Atlantic coast of Africa, which would be a fundamental key in the Age of Discoveries.
This chart is housed in the Biblioteca Estense e Universitaria in Modena, under the shelfmark C.G.A.5.c.
The Mystery of the Author and Date
Neither the author nor the date of creation of the chart is known. Although it is commonly accepted that it is a Portuguese work, scholars do not agree about its date of production.
In 1938, the Portuguese scholar Fontoura da Costa suggested that the chart was made around 1471, arguing that the southernmost place name recorded on it is rio do lago (the Lago River), which was discovered by João de Santarem and Pêro Escobar early that year.
Armando Cortesão did not agree with this theory, arguing that there was no strong evidence that the chart was made immediately after the voyages of Santarem and Escobar.
Some years later, Pinheiro Marqués contended that no astronomical data was used in the drawing of the coast of Guinea; consequently, the chart had to be made before the hydrographical survey of the Gulf of Guinea ordered by King João II in c. 1485. Thus, he proposed that the chart should be dated ca. 1471-82.
We have 3 facsimiles of the manuscript "Portulan C.G.A.5.c":
- Portolano C.G.A.5.c (map in tube) facsimile edition published by Il Bulino, edizioni d'arte, 2002
- Portolani (set of 3 maps in case, includes C.G.A.5.c) facsimile edition published by Il Bulino, edizioni d'arte, 2004
- Portolani (set of 3 maps in deluxe wooden case, includes C.G.A.5.c) facsimile edition published by Il Bulino, edizioni d'arte, 2004