Terra Australis (Incognita) was depicted by the majority of medieval cartographers as a huge southern continent many times the size of Antarctica, in a variety of shapes such as those shown in Figures 1.1 to 1.4 below. A high resolution scan of the Desceliers world map (catalogue number French MS. 1*) can be purchased from the John Rylands Library, University of Manchester, but may be reproduced only by recognized institutions and permission to show a reduced size image on this website has been denied. The polar view adapted from the original is shown in Figure 1.3. Since Antarctica was discovered only in 1820, it seems to be universally accepted amongst modern scholars that Terra Australis was an imaginary continent dreamt up by medieval cartographers who argued that it had to exist to balance the land masses in the northern hemisphere. The chief proponent of this theory was Gerhard Mercator, who documented these arguments in detail. Maps showing Terra Australis however appeared before Mercator was born and he was therefore clearly not the inventor Terra Australis, although he may have been the first to attempt to rationalize its existence.

When I began studying the medieval maps of the world, I found it increasingly difficult to believe that it could all have been nothing but a figment of someone’s imagination. Furthermore, if it had actually existed, Terra Australis would be the prime candidate for Plato’s sunken continent of Atlantis as much of it today lies beneath the ocean.



Figure 1.1. Ortelius World Map 1570 [Theatrum Orbis Terrarum - Ortelius Atlas]. Note the immense continent in the south.
Download a high resolution image here (2.8 MB)

[Complete atlas with higher resolution maps available here]

Figure 1.2. Schöner’s 1524 map of Terra Australis




Figure 1.3. Polar view of world map of Desceliers 1546 [adapted from the original map at John Rylands Library, (French MS. 1*)]




Figure 1.4. Mercator’s 1569 World Map [BnF, Paris]

Download a high resolution image here.

In my original theory presented here I paid relatively little attention to Terra Australis itself, arguing that the medieval maps contain information that pertains to an era long before the voyages of Christopher Columbus, and that it would not have been possible to map the entire world within such a short time span given the primitive boats and equipment available at that time. In other words, the medieval maps were based on much older maps created by an earlier sea-faring people who could not literally have made such a large mistake as Terra Australis.

I have since been able to take a much closer look at Terra Australis itself and through comments and questions received from readers, have been able to expand my argument substantially.  I only recently became aware of altogether different representations of Terra Australis Incognita, in which the continent is shown as having an inland sea (Figure 1.5 [Chet van Duzer, Cartographic Invention: The Southern Continent on Vatican MS Urb. Lat. 274, Folios 73v-74r, Imago Mundi Vol. 59, Part 2: 193-222, 2007]) as well as being C-shaped (Figure 1.6).



Figure 1.5. Ring-shaped Terra Australis on the Vatican Map ca. 1530 [Vatican Library / Van Duzer]


Figure 1.6. C-shaped Terra Australis on the 1515 globe by Schöner, original map with gores (left) and converted to polar format by the author (right)