Why is this map entitled Ptolemy’s world map, when it was made more than 1000 years after Ptolemy’s death?
Ptolemy (c.100-178) was a hugely important geographer and astronomer working in Ancient Rome. This map takes valuable information from his famous book Geographia. His work informed mapmakers on the size of the Earth, and the co-ordinates for the positions of all the places and features indicated on the map.
Until a copy of Geographia was translated from Greek into Latin in 1407, all knowledge of these co-ordinates had been lost in the West. The book created a sensation, as it challenged the very basis of medieval mapmaking – mapmakers before this had based the proportions of countries, not on mathematical calculations, but on the importance of different places - the more important a country was, the bigger it appeared on the map. In fact, many of Ptolemy’s calculations were later proved to be incorrect. However, the introduction of mathematics and the idea of accurate measurement were to change the nature of European mapmaking forever.