Ptolemy’s World Map — The pinnacle of map making in Antiquity

The world at the beginning of the 2nd century CE was one of great empires. In the east, the Han Empire had consolidated its control at home and was expanding into central Asia. In part seeking the famous horses of the Bactrian Kingdom resulting in the first and only direct clash between the Chinese and Hellenic worlds.

In India, the Kushan Empire was spreading further into the subcontinent, taking its unique blend of Greek, Bactrian, Persian, and Indian culture with it.

Meanwhile, in the west, the Roman Empire stood strong. With the appointment of the Emperor Nerva to the Principate after the assassination of Domitian, the period of Roman rulers known as the five good Emperors began. A period in which Rome would attain the absolute zenith of its power and territory, the height of the Pax Romana, the longest period of peace the Mediterranean world has ever experienced.

The Roman Empire in 117 CE

The west would never see such a period of unity and peace again. The optimism and purpose created by the Empire, provided the perfect conditions for an era of unprecedented inquiry and growth. A new spirit of examining and documenting the world led to some significant advancements. Among these were the continued development of the discipline of geography.

From these inquiries another world map would be created, more detailed and wider ranging than any I have explored previously, representing the apex of knowledge of the world in antiquity. For this map we must thank a man named Claudius Ptolemy, a Greco-Roman Scholar living from roughly 90 CE to 168 CE. This is the 9th article in a series, you do not have to have read parts 1, 2, 3, 4, 5, 6, 7, and 8 to follow this article, but they do provide context and come together as a greater whole.

With the fall of the Julio-Claudian dynasty and the short and bloody civil war in the year 68 CE, known as the year of the four emperors, Rome had its first taste of a contested imperial transition. Such civil wars and contests for the imperial throne would later weaken the Empire and arguably be a significant factor in its eventual fall. However, that was all yet to come and with the rise of Vespasian and the Flavian dynasty, the general peace and consolidation of empire would continue, with the Roman empire now encompassing almost the entirety of the geographical area of what I am terming antiquity. Claudius Ptolemy’s life would co-inside with the end of the Flavian dynasty and most of the Nerva-Antonine dynasty. In his time, he would therefore be a witness to Trajan’s wars of expansion, taking Rome to his greatest territorial extent, the vast building projects of Hadrian and in his final days the Antonine plague which ravaged the Empire during the reigns of Antonius Pius and Marcus Aurelius.

Ptolemy’s name suggests that he was a native of Egypt of Greek decent, however, his first name also suggests Roman citizenship. This is an important mix as it means that Ptolemy was a man with access to the knowledge of three of the great civilisations of the ancient Mediterranean.

Ptolemy worked at the Royal Library of Alexandria, the greatest library of the ancient world and the most famous of antiquity. The library formed part of a research institute in Alexandria, a Temple of the Muses constructed under the orders of Ptolemy I (366 BCE — 282 BCE) for the gathering of all the knowledge of the world in one place. In many ways it was the culmination of the Greek thirst for knowledge which had grown up over the preceding centuries. The conquests of Alexander the Great had led to an explosion of information about the world flooding into Greek hands.

Alexander’s new city on the Nile became the collection point for this vast bank of information. Under the Ptolemaic kings, the library of Alexandria was nurtured. Intellectuals from all over the Greek world were encouraged to come there, a level of patronage and prestige which would continue after the Roman conquest of Egypt in 31 BCE. Estimates vary, but undoubtedly the library held a vast number of books, figures range from 200,000 to 700,000, the library of Alexandria was the internet of its day.

This environment gave Ptolemy the perfect setting in which to develop many different interests. As well as geography, Ptolemy also wrote books on music, optics, geocentric astronomy, and astrology. However, for the purpose of this piece, we are most interested in his work mapping the world.

Ptolemy drew on a centuries old tradition forming the basis for the now established discipline of geography dating back to Eratosthenes in the 3rd century BCE and beyond. In applying geometry and mathematics to the study of the Earth, he produced a textbook called On Geography in roughly 150 CE. This work is important most of all for laying out Ptolemy’s method for projecting the globe onto a flat piece of paper, a first for map makers and his technique remained the template in the west for the next thousand years. Ptolemy’s work explained how to draw both regional and world maps and listed 8,000 places within the world of antiquity.

Looking at Ptolemy’s map, what can it tell us about the world of the 2nd Century CE?

Claudius Ptolemy’s world map

West to east, the map stretches from the Canary Islands to Korea, showing that the Romans had at least some knowledge of what lay far beyond the limits of their Empire.

The northern most point of Ptolemy’s map is a place he names Thule, a land mentioned by numerous of his predecessors, with Pytheas of Massalia even claiming to have visited it. As you can see below, it appears as an island to the north of Britain, leading to speculation that it is a representation of the Orkneys or possibly even somewhere in Scandinavia.

In the south, the map reaches down to Saharan Africa, however, this is then joined to southeast Asia. Of course, there are no Americas in Ptolemy’s work and the Pacific is also missed out. This all goes to suggest a Roman view of the world much smaller than reality and the Mediterranean is placed firmly at the centre. This may reflect what was thought to be reality, although it is equally likely that it is a representation of the Empire’s sense of importance in a world and time where it was utterly dominant. A way of thinking and presenting maps seen as far back as Anaximander and Hecataeus of Miletus and possibly even the Babylonian World Map. A further clue perhaps given to this mindset is that Ptolemy’s map overestimates the length of the Mediterranean by 61 degrees.

Ptolemy’s Mediterranean

Looking closer, we can see that the Mediterranean is the most detailed part of the map. The Romans, and Greeks before them, had been sailing the Mediterranean for centuries, its coasts and surrounding lands were well known to them. This detail is therefore not surprising.

It is when we look towards the edges of the map, that things get a little more interesting.

Ptolemy’s depiction of the British Isles is intriguing. The southern part of the island of Britain had been under Roman control for almost 100 years when Ptolemy produced his map, and many expeditions had been launched into the wild north. However, continuing a common feature of classical maps, Scotland is depicted east to west as opposed to north to south, perhaps showing a lack of detailed knowledge on the wild fringe of empire.

The limit of knowledge is further displayed when looking to Africa. Ptolemy believed the world south of the equator to be uninhabited. He shows North Africa being connected by a series of lakes and rivers where now we would find only desert. Everything below these waterways is described as terra incognita, showing a lack of knowledge or perhaps interest from his Roman audience.

Africa and the Southern regions of the world

However, despite the sketchy detail on the fringe of the Empire, further east Ptolemy displays some grasp of civilised life beyond Roman power. The furthermost point of the map is the port of Cattigara, way off to the East. Speculation surrounds where this port may be, theories include China and Korea and perhaps more surprisingly the west coast of the Americas. What we can say is that Roman civilisation was aware of societies existing far to their east, well beyond the limits of imperial control.

The Golden Chersonesus

The limits of Roman knowledge of the east are clearly on display in Ptolemy’s work. There is a peninsula known as the “Golden Chersonesus” perhaps a representation of the Malay peninsula, the obscurity of this place would draw later explorers like Columbus and Vasco Da Gama.

Perhaps the most enigmatic location on Ptolemy’s map is the island of “Taprobana”. Larger than Britain and found somewhere near what is now Sri Lanka. The land is traversed by the equator and could have been depicting anywhere from Eastern Africa to Indonesia.


In creating the map, Ptolemy introduced a basic graticule, or grid of coordinates and using latitude and longitude acquired from the vast knowledge of his predecessors, plotted the inhabited world, which he called the Ecumene. These were important steps forward, although Ptolemy did make some errors, underestimating the circumference of the earth for example. However, as noted above, Ptolemy’s work became the base line for all subsequent works in the west for 1000 years and arguably the elements he introduced and presented on his map have become a standard which we still follow to this day. This map, therefore, not only represents the apex of map making in antiquity but is in many ways the first modern world map, and the principles behind it developed, reinforced, and became the foundations for modern cartography and geography.

To conclude, Ptolemy’s map shows us that the Roman Empire at its height had a detailed knowledge of itself and a growing knowledge and curiosity about the world around it. A sense of importance which any powerful Empire is guilty of may have placed the Mediterranean at the centre of the world, but Romans were aware of what lay outside their borders and interested to know more.

Most importantly, Ptolemy’s work gave the west the foundation from which to build. For more than a thousand years the system Ptolemy created could not be bettered. When it was finally overcome, the works which followed built on Ptolemy’s ideas rather than discarding them. Most of all perhaps, works like this inspired curiosity in others to go out and explore, filling in the “Terra incognita” of the Roman conception of the world.

However, this would all come much later. Ptolemy’s work is one of triumph with a hint of melancholy for those of us looking back upon it across the broad sweep of history. The scholars of antiquity who followed him would be unable to build upon his efforts. As the grasp of Rome on the Mediterranean world began to weaken and the western provinces were released to spiral out of control, many of the advancements in the discipline of geography would be lost or sit in stasis until they were found and used once again many centuries later. To illustrate this decline, the next and final article in this series will examine the Peutinger Map, the last world map we have before the fall of the western empire and the end of antiquity.



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Lewis D'Ambra

Lewis D'Ambra

I write about history and its echoes and lessons for the present.