(An intermittent series introducing well known maps)

The Pyramid of the Sun is being built in Teotihuacan.

Antoninus Pius is Emperor of Rome.

The Moche culture is beginning in Peru.

The Antonine Wall is being built in Scotland.

Ptolemy’s Almagest is published. (Astronomy)

Galen is studying medicine.

Hadrian’s Wall was completed 20 years earlier.

Ptolemy’s Geographica is published.


Claudius Ptolemy (85-165 CE), mathematician, astronomer, geographer and astrologer, had a major impact on the world of cartography in the Middle Ages.  Writing in Alexandria, Egypt, Ptolemy was an exceptional scientist for his time.  His published works include treatises in astrology, astronomy, geography and other subjects, some of which were very influential in Medieval and Renaissance scientific thought.  Among these were Almagest”  and Geographia“.

“Almagest” is the only known comprehensive text on astronomy to survive from ancient times.  It was the accepted authoritative source for most of the Western World during the Medieval Period.  In it, Ptolemy proposed the Geocentric theory, attempting to make sense of the motions of the stars and planets he observed in the night sky.  This earth centered model for how the universe worked, would be accepted for nearly 1200 years.  It was not until the publication of On the Revolutions of the Heavenly Spheres by Nicolaus Copernicus in 1543, that the scientific world would begin to accept the Heliocentric theory.

Another very influential work was Ptolemy’s “Geographia”.  Although its name implies that it was an atlas, in actual fact, the majority of the book is simply a list of coordinates.  If Ptolemy created actual maps to accompany the book, none have been located.  Building on earlier works of such notables as Marinus of Tyre , Ptolemy revised Marinus’ assigned Latitude & Longitude coordinates, added a system of meridians and created three map projections.  For Ptolemy, the known world extended from the Fortunate Isles  (perhaps the Azores or Canary Islands) to Serica (China along the Silk Road) or about 180 degrees of longitude. And from Thule (possibly the Orkney or Shetland Islands) to anti-Meroe (East Africa below the equator) or about 80 degrees of latitude.

Western Rome began to fall into disarray only a few hundred years after Ptolemy’s death.  Scholarship lapsed and much of the earlier knowledge was lost.  Fortunately, the Eastern part of the Roman Empire or Byzantine Empire as it became known, survived into Europe’s Middle Ages. Classical scholarship thrived there and grew.  Sometime in the 9th Century, Ptolemy’s work was translated from Greek into Arabic. Then in 1295, Byzantine monk Maximus Planudes,  translated the Geographia” into Latin.  Planudes, assisted by other monks, used the coordinates to produce the maps we have now.  The invention of wood cut printing and later the printing press, brought Ptolemy’s work to wider audiences in Italy, France and Germany.

Later map makers were influenced by “Geographia”.  It is very clear that Martin Waldseemuller was being influenced by Ptolemy’s work in the early 1500’s.  His world map of 1507 follows one of Ptolemy’s projections, although it encompasses more of the earth.  Waldseemuller also includes 2 figures at the top of his map.  One is Ptolemy, the other is Amerigo Vespucci whose name was written on the new world.  {For more information about the Waldseemuller world map, please see the post entitled “1507” September 2018}

With the ability to widely disseminate printed materials including maps, a general reawakening of scholarship began in Europe.  Primarily fueled by economic factors, an intense interest in exploration developed.  The “Golden Age” of cartography had begun.  Claudius Ptolemy’s works, especially “Geographica”, played a key role.



Ohio State University Library has these resources:

Achievements and Legacy of Ptolemy

The Geography / Claudius Ptolemy


Ptolemy’s Almagest

Tetrabiblos / Ptolemy