Many of history’s major breakthroughs were made by great thinkers standing on the shoulders of other intellectual giants, and Ptolemy’s Geographia, which builds on the scientific advancements of ancient Greek scholars, is no exception.
The ancient Greeks were particularly skilled at understanding the world around them. By the fifth century BCE, the famous mathematician Pythagoras understood that the Earth was round, and it wasn’t long before Eratosthenes, another Greek scholar, accurately calculated the planet’s circumference.
Centuries later, the Egyptian Greek scholar Ptolemy channeled all these scientific advancements into his masterwork, a collection of maps known as Geographia. Created around the year 150 CE, the eight-volume atlas served as a blueprint for mapmaking during the time of the Roman Empire. Ptolemy detailed the process of projecting a globe-shaped object onto a two-dimensional map, and pinpointed some 8,000 locations throughout Eurasia and northern Africa. He borrowed the concept of longitude and latitude from his mapmaking contemporary Marinus of Tyre, and built on it to make his own lasting contributions to cartography. Ptolemy’s work fueled many of the maps to come during the Islamic Golden Age and Europe’s Renaissance era.
Reprinted from HistoryFacts.com article