Ptolemy's Mappamundi

The Greek geographer Claudius Ptolemy wrote his Geography, also known as Cosmographia, in the 2nd century CE. This work is considered the first cartographical treatise with a mathematical and astronomical basis. It includes more than 5,000 places in the known world, complemented by various maps.

Ptolemy's work was translated into Latin in the 15th century, becoming a reference for the study of the world. It includes the Mediterranean Sea surrounded by the lands that were known of at the time, and features a large number of place names.

The world known to Ptolemy spanned around 180 degrees of longitude. In reality, this was exaggerated, because the Earth was considered to be around one fourth smaller than it really is. This incorrect estimation of longitude continued until the early 16th century, when an expedition set sail to the Maluku (formerly the Moluccas or Spice) Islands, shortening the sailing distance from Europe to the Indies substantially via a route to the west.

Ptolemy believed that the Indian Ocean was an enclosed sea and therefore impossible to reach by boat from Europe.

This fact was corrected in 1488, when the Portuguese sailor Bartolomeu Dias rounded the Cape of Good Hope in Africa.

The existence of the Americas was also unknown. These continents were added to maps in 1492, when Columbus landed there.

So, although Ptolemy's Geography continued to have a significant influence in the time of Ferdinand Magellan and Juan Sebastián Elcano, its view of the world had become outdated by Spanish and Portuguese discoveries.

The work kept at Madrid's Naval Museum (Museo Naval) is a later reproduction based on the original work. It was created in the 15th century by Jacopo d'Angelo, who produced a translation of the original.