Unlike the standard portolans of the time which were usually covered with rich and colorful motifs, this one has little decoration.
It shows the Mediterranean Sea. Only the Mediterranean coast of the Iberian Peninsula has been drawn and the course system originates between Sicily and Greece.
The map features an image of the Virgin and Child, which was commonplace for medieval portolans. Next to it is an inscription: "Joan Martines en Messina Añy 1565" (Joan Martines, Messina, 1565). Joan Martines was a cartographer working in Messina between 1556 and 1587. He was appointed royal cosmographer by Philip II, then including the words "cosmógrafo de S.M" (H.M. Cosmographer) on his maps. He moved to Naples to serve the Spanish crown and produced over 30 atlases and maps between 1556 and 1591.
The discovery of America had a profound impact on the maps produced by the Spanish crown, shifting the focus of interest from the Mediterranean ports to the coasts of the new continent. As a result, some of the main cartographic workshops moved to other Mediterranean locations ruled by the Spanish crown, such as Messina.
Medieval "portolans" (also called "portolan charts") were cartographic instruments that, together with other nautical equipment such as compasses, became indispensable tools allowing ships to move safely around the Mediterranean coastline. Their origins can be traced back to the "peripli" manuscripts used to record oral descriptions of coastal routes by Greek and Roman navigators. In time these developed into "portolan charts": a geographical summary including port characteristics, approximate distances between coastal features, river mouths, anchorage information, and any other references that a seafarer might find useful on their journey. This information was written on parchment or a similar material, resulting in what are now known as nautical or portolan charts.
Portolan charts were first created in the Middle Ages (13th century) and were produced until the Early Modern Period. They were originally made in a region of the Mediterranean where there were intensive political, commercial, and cultural links between cities. Major centers of map production included Majorca, Genoa, and Venice.