Cantino Planisphere (1502): A Smuggled Portuguese World Map

The Cantino planisphere is a Portuguese world map made in Lisbon around 1502 and secretly sent to Italy. It is the oldest surviving Portuguese chart to show the new Portuguese discoveries in both directions at once: the sea route around Africa to India and the coasts of Brazil and Newfoundland in the west. Drawn with the line of the Treaty of Tordesillas, it captures how Europeans saw the world only ten years after Columbus’s first voyage.

How the map reached Italy

In the early 1500s Italian rulers were keen to learn about Portugal’s discoveries, which threatened Venice’s spice trade with the East. Ercole I d’Este, Duke of Ferrara, employed an agent in Lisbon called Alberto Cantino, ostensibly to deal in horses.

Cantino had a world map made, most likely copied by an unnamed Portuguese cartographer from the official master chart kept by the crown. An inscription on the back records that it cost 12 gold ducats. By late 1502 the map had reached Italy and was in the duke’s collection in Ferrara.

Portugal is often said to have kept its geographical knowledge secret, the so-called policy of secrecy. Historians disagree about how strict this really was, but the Cantino map is frequently cited as an example of how hard such knowledge was to contain.

What the map shows

The map is drawn on several sheets of parchment joined together, measuring about 220 by 105 centimetres (about 7 by 3.5 feet). It is richly coloured, with flags, city views and decorations, and covered with a network of compass lines typical of nautical charts.

Its most important features include:

• The Tordesillas line: a north–south line west of the Cape Verde Islands marking the division agreed by Spain and Portugal in the Treaty of Tordesillas of 1494.
• Brazil: the coast reached by Pedro Álvares Cabral in 1500, shown with trees and colourful parrots east of the line.
• Newfoundland: a large land in the North Atlantic with Portuguese flags, recording the Corte-Real voyages and placed east of the line, in Portugal’s zone.
• The Caribbean: the islands found by Columbus, with the Spanish discoveries west of the line.
• Africa and India: a remarkably accurate outline of the African coast and the route to India pioneered by Vasco da Gama, with Portuguese trading posts.

The map also marks the Equator, the Tropics and the Arctic Circle, giving a framework of latitude. It has no grid of longitude, which navigators could not yet measure at sea.

Who made it

The cartographer is not named on the map. Because it was copied in Lisbon from Portuguese sources, it is usually attributed to an anonymous Portuguese mapmaker working with access to the royal charts kept at the Casa da Índia, the crown’s trading house for the Indies. Attempts to link it to a specific known cartographer have not produced a consensus.

The map was clearly made for display rather than for use at sea. Its decoration, including a drawing of the Portuguese fortress of São Jorge da Mina on the Gold Coast of West Africa, was meant to impress a princely patron. Yet its coastlines rest on real pilots’ charts, which is what makes it so valuable to historians.

Puzzles and debates

North-west of Cuba the map shows a long coastline that some historians identify as Florida or the eastern coast of North America. If so, it would reflect voyages not otherwise recorded before Juan Ponce de León reached Florida in 1513. Others believe it is a misplaced portion of Cuba or a mapmaker’s guess. The question remains open.

The position of Newfoundland is also telling. In reality it lies far west of the Tordesillas line. Placing it on the Portuguese side reflects both the difficulty of measuring longitude and Portugal’s political interest in claiming the land.

A turbulent history

When the Este family lost Ferrara to the Papal States in 1598, they moved their court and library to Modena, taking the map with them. In 1859, during the political upheavals of Italian unification, it was stolen from the ducal palace.

In 1868 Giuseppe Boni, director of the Biblioteca Estense, found it in Modena, reportedly being used as a screen in a butcher’s shop. He bought it back and returned it to the library. It is kept today in the Biblioteca Estense Universitaria in Modena.

Timeline

• 1494: Spain and Portugal sign the Treaty of Tordesillas.
• 1498: Vasco da Gama reaches India.
• 1500: Cabral reaches Brazil; Gaspar Corte-Real begins his North Atlantic voyages.
• 1502: Cantino obtains the map in Lisbon and sends it to Ferrara.
• 1598: The Este collections move from Ferrara to Modena.
• 1859: The map is stolen in Modena.
• 1868: Giuseppe Boni recovers the map.

Why it matters

The Cantino planisphere is a snapshot of a world being redrawn. Within a single decade, Europeans had reached the Americas and found a sea route to India, and this map shows both achievements side by side, along with the treaty line meant to divide them. It is also a reminder that maps were valuable political and commercial secrets in the age of exploration.