Portrait of a Chartmaker by Pietro Vesconti anno 1318
While there is no consensus regarding the origins of portolan charts, the longevity of their manufacture and use is attested to by myriad extant examples, with charts being created and used for navigating as recently as the 18th century. The earliest known extant chart as we write is the Carte Pisane, described in part I of this series. This chart is quite devoid of embellishment or decoration of any kind. Its rhumb lines and toponyms along the coasts depicted create outlines of the continents, the shores of a portion of the Black Sea, along with a few islands. It was obviously a useful tool for plotting routes for maritime travel and trade.
In Portolan Charts II we discussed 14th century portolans and featured the Cortona Chart, which dates to approximately the turn of the century, just a few years after the creation of Carte Pisane. Within that short period of time, changes had already taken place and considerable inland topography, replete with toponyms, evidenced transition to a more elaborate and increasingly detailed chart. The compass or wind rose, used to orient charts, is missing from the Pisane but soon it would become a permanent fixture in portolans. Other details appearing with increasing frequency include symbols for depth soundings, safe anchorages, and dangerous regions such as shoals, sand bars, rocky outcroppings, etc.
Portolan Charts III focused on the Dulcert Chart of 1339, one of the three known extant charts to have been created by Angelino Dulcert, one of the early members of the famed Majorcan school of chart and map making. The chart is remarkable particularly for the significant increase of elements in its design which were not typically included in charts of its era, especially in its delineation of inland regions and territories and its use of toponyms for those regions. Other of its unusual features include the use of heraldic devices, the inclusion of toponyms including city and regional names, along with river systems and islands. Most of its many coastlines are remarkably accurate, as were those to follow in later charts. It is demonstrably true that the accuracy of many of the early charts’ depictions of coastlines was rarely surpassed until the eighteenth century. This blog in our Portolan Chart series will look at some of the better known and more elaborate charts which are extant today.
According to various sources, many if not most of the extant charts were unlikely to have gone to sea, as production costs would have been particularly prohibitive for a utilitarian object which would be subject to the damp and unfavorable conditions of early seaworthy vessels. Thus it is probable that portolans used at sea were far less elaborate than surviving charts, and perhaps published on materials other than vellum. Indeed, remnants of portolan style charts survive in materials other than vellum, with papyrus being most common. Maps and charts were, from antiquity, not only useful and necessary for safe travel, but were also elegant status symbols which decorated the walls of the castles and palaces of the powerful and wealthy, and the lineage of many extant charts and maps can be traced through the chronicles of libraries in private estates.
Early references to charts and maps appear often in antiquity, with some of the most common references to the works of cartographer/mathematician Marinus of Tyre, the ancient port city in modern-day Lebanon. Marinus is known to have created sea charts in the second century CE, employing his vast erudition in the field of mathematics, along with reports and itineraries of navigators of his day to create his charts. Ptolemy of Alexandria, whose work Geographia was used by myriad later cartographers for creating maps and charts, is well-known even today due to the number of maps based on his work. However, the direct influence of their works on the development of portolans is yet to be determined. In lieu of concrete evidence of those links, we present images of finished products which have survived millennia and are still as extravagantly beautiful and informative as at the time of their creation.
Different schools with differing approaches appeared throughout the history of the production of portolan charts. Workshops are known to have existed in Genoa, Venice, and Majorca where both maps and sea charts were made. Styles varied from a more conservative model in most Italian workshops, to the more elaborate and often fanciful style of the Catalans. Many of the most visually stunning charts featured in this blog are from Catalan workshops. It is our hope that this series of blogs concerning portolan charts might inspire you to research this remarkable genre, one which as of yet has many unknowns to be resolved.
1466 Portolan Chart by Petrus Roselli - Catalan school.
1584 Portolan Chart by Joan Martinez - Italian cartographer
Compass Rose from a Portolan Chart
The rose is one of the most important contributions of the genre.