Terra Australis

Terra Australis (Latin for South Land) was a hypothetical continent first posited in Antiquity and which appeared on maps between the 15th and 18th centuries. Although the landmass was drawn onto maps, Terra Australis was not based on any actual surveying of such a landmass but rather based on the hypothesis that continents in the Northern Hemisphere should be balanced by land in the south. This theory of balancing land has been documented as early as the 5th century on maps by Macrobius, who uses the term Australis on his maps.

In the early 1800s, British explorer Matthew Flinders had popularized the naming of Australia after Terra Australis, giving his rationale that there was "no probability" of finding any significant land mass anywhere more south than Australia. The continent that would come to be named Antarctica would be explored decades after Flinders' 1814 book on Australia, which he had titled A Voyage to Terra Australis, and after his naming switch had gained popularity.