194 emilie savage-smith
The earliest surviving European “portolan” or sea chart for the Mediterranean was
produced in Italy at about the same time that the great medieval world maps
(mappaemundi) were being made in England and France—that is, in the second half
of the thirteenth century. The sea chart is usually attributed to a workshop in Pisa,
hence its common name Carte Pisane, though others have argued for Genoa (see
Campbell, 1987: plate 30; Billion, 2011). The European portolan charts incorporated
lists of ports onto drawings of coastlines far more detailed than those on the eleventh-
century map in the Book of Curiosities.
In the European charts, the Mediterranean map was overlaid by a fretwork of inter-
secting lines (called “rhumb” lines) linking points on the circumferences of invisible
circles. The radiating lines could serve both as copying aids for the chart-maker and
as navigational aids, with the lines representing wind directions. The development of
portolan or sea charts with rhumb lines was perhaps linked to the development of
simple magnetic compasses in the twelfth century, though this is a debated issue.
Their production, however, did not require a high level of mathematical skill. As Peter
Barber has noted: “Because the Mediterranean is so narrow, lying between only a few
degrees of latitude, and comparatively short in breadth, coastal outlines could be
drawn with relative accuracy without the need for a mathematically determined pro-
jection to take account of the earth’s curvature, the calculation of which would have
been beyond the capabilities of most medieval sailors” (Barber, 2005: 62).
Catalonia as well as Italy became famous for the production of portolan charts
(Campbell, 1987; Kretschmer, 1909; Gautier Dalché, 1995; Gautier Dalché, 2003;
Pujades i Bataller, 2007). An example of an Italian portolan chart made by Placido
Caloiro about 1665 is shown on the cover of this book. The palm trees in North
Africa and the Holy Land are marked by three crosses; on the neck of the chart is a
medallion with Mother and Child. The island of Rhodes (near the south-west coast of
Turkey) is marked by a cross, more than a century after the Knights Hospitaller
ceased to occupy it in 1523.
The overall design of portolan charts, with their realistic shorelines, suggests a
practical use for Mediterranean navigation. However, while some of the European
ones were apparently prepared as working navigational charts, the examples surviving
today provide little evidence of having been used for such a purpose.^4 Rather, they
appear for the most part to have been prepared as colorful and impressive emblems of
empire. On the charts made in Italy colorful banners occupy the interior land masses,
claiming the regions on behalf of various rulers, while the products of Catalan chart
makers are even more decorative, with elaborate portraits of rulers occupying their
respective territories.
The workshops of Ottoman chart makers in the eastern Mediterranean were pre-
dominantly influenced by the Italian school of portolan chart makers. Of the Ottoman
chart makers, the most famous is Pı̄rı Rē ͗ıs (d. 1554), possibly born in Gallipoli and, ̄
like his father, an Ottoman naval officer. His Book of Maritime Matters (Kitāb-i
baḥriye) is a manual of sailing directions, illustrated with individual islands and main-
land shorelines of the Mediterranean, which he also called “The Romano-Byzantine
Sea (Baḥr-i Rūm).” The book was composed in two versions, one completed in 1521
and the other in 1526. Neither version included a map showing the entire
Mediterranean at one time, though such maps have been added to some later copies
(Brummett, 2007: fig. 1).