Detail of the Carte Pisane 1275 - 1300
This detail of the Carte Pisane, the oldest known portolan chart, depicts the coastlines of the western and central regions of the Mediterranean, including the ‘boot’ of Italy, the Adriatic Sea and much of its coast, along with a portion of the northern coast of Africa.
Advent of Portolan Charts
The advent of portolan charts in medieval Europe was a pivotal moment in the history of European navigation and cartography. Portolans were the most accurate cartographic works of their time for mariners, furnishing a practical tool for their voyages through unknown or perilous waters. Distance, direction and coastal features were provided by the charts, with rhumb lines enabling navigators to calculate and measure the direction and progress of their vessels as they sailed.
Created to be durable, portolan charts were manuscripts - hand drawn in ink on vellum, a costly, durable material prepared from animal skins by removing the hair, scraping, stretching and bleaching until a fine writing surface has been created. The charts are usually fitted to the available surface, sometimes sacrificing varying degrees of accuracy in order to fit the chart within the confines of the skin.
The etymology of the word 'portolan' can be traced back to its Latin root, port. The Italian term portolano alludes to the charts’ emphasis on landmarks such as coastlines, harbors, and ports - information vital for safe navigation. The plural forms 'portolans' and 'portolani' are both often used. Italy is considered to be the birthplace of portolan charts, with other production centres appearing later.
The charts were used along with mariners’ instruments, the stars, and books featuring navigational information. The earliest known extant charts suggest that they were initially confined to charting Europe's Mediterranean basin and the shores and a few islands of the eastern Atlantic, but within decades of the creation of the Carte Pisane, portolans came to share many features with topographic maps.
The primary difference between portolan charts and topographic maps is that the charts feature toponyms for ports, settlements and cities along shorelines, and include rhumb lines for navigational purposes, while topographical maps depict inland toponyms and topography as well as coastal. The outline of the coasts depicted in many portolans is often so accurate in places as to be almost comparable to modern satellite imagery of those areas. The charts also labeled dangerous areas in the sea and along the coasts, faciltating safer sailing.
The origin of portolan charts remains a bit of a mystery, as they seem to have arrived on the scene fully formed with flimsy evidence suggesting precursors. However, scientific progress is and always has been achieved in incremental steps by reviewing, analyzing, and evaluating previous work, and myriad theories have been posited regarding their appearance in the thirteenth century. One of the more interesting theories, and perhaps more feasible, concerns early sea trade routes of the Roman Empire, routes often overlooked perhaps due to their closure as the Empire's power declined - routes which surely would have been mapped.
One of the most lucrative maritime trade routes of the Roman Empire was the Indian Ocean Trade route, linking Rome to the far reaches of the known world, including India and China. Each year mercantile vessels laden with olive oil and other Mediterranean commodities would set sail from Egypt’s Red Sea ports and sail east, eventually reaching India. Ships returning home brought exotic goods from the Orient such as silk, gemstones, and spices. This trade transformed Roman society, providing access to marvelous luxuries previously unknown or inaccessible to them.
Ancient authors wrote of the maritime commerce of Rome with realms to the east, and it is not only possible but highly probable that there were maritime maps drawn on papyrus or vellum for navigating these long voyages. That charts used at sea no longer exist is not surprising. Dampness and constant use would wear out even the highest quality vellum quickly enough, and papyrus even faster. The great libraries of antiquity including those of Alexandria, Antioch, Pergamum, Ephesus, Pergamum, Nineveh and Constantinople all would have been good depositories for copies of such maps, but these libraries have not survived, and to date legitimate ancestors of portolans have not surfaced, though it is altogether possible that some do exist somewhere, as of yet unfound.
Carte Pisane
The Carte Pisane was purchased from a family in Pisa (thus its name) in the 19th century by the Bibliotheque nationale de France, where it resides to this day. It is one of the largest known portolans, measuring 19.76 x 41 inches, with only four other known examples of similar size. Despite uncertainty and some controversy regarding its date, it is often referred to as the oldest extant nautical map, with most researchers dating it to the late 13th century. Its author is unknown but it is thought to have been made in Genoa.
Drawn on a large piece of vellum which includes the neck of the animal, it covers the Mediterranean shores, a bit of the western seaboard of both Africa and Europe, a region of the Black Sea in the Crimea, along with a few islands, including England, in the west Atlantic. Its accuracy is remarkable in some places, is such that it is sometimes compared to modern satellite imagery. Carte Pisane focuses primarily on practical navigational details, including symbols indicating hazards for mariners, but otherwise is quite devoid of decoration.
The outline traced by the toponyms of the Carte Pisane reflects what was known of the coastal regions at the time the chart was created. Therefore, it is not surprising to see a well-defined Mediterranean basin, as its waters had been plied for millennia before the chart's time, and myriad descriptions of it in textual and possibly even map form would have been available to the creators of the chart, and there would have been direct contact with mariners regarding the results of recent voyages.
The chart's representation of England has been called a pre-cartographic depiction, one thought to be based on unreliable, vocally transmitted information. Despite the source, it features six toponyms, with London included. Altogether the chart's toponyms number approximately 680. Due to loss of vellum in places, it may be assumed that there were more, perhaps including coastlines and toponyms of the Black Sea in addition to the west coast of the Crimean region, which is delineated and easily recognizable.
Carte Pisane