The cartographers who did most to shape how we draw the world are Claudius Ptolemy, who catalogued about 8,000 places in Alexandria around 150 AD; Pei Xiu, who set out six principles of scaled mapping for China’s Jin dynasty in the 260s; Muhammad al-Idrisi, who finished the 70-map Tabula Rogeriana for Roger II of Sicily in 1154; Fra Mauro and Piri Reis, whose world maps of about 1450 and 1513 stretched medieval knowledge to its limit; Martin Waldseemüller, Abraham Ortelius and Gerardus Mercator, who between 1507 and 1595 gave us the name “America”, the modern atlas and the navigator’s projection; the Cassini family and the surveyors of India, who measured whole countries by triangulation; and Marie Tharp, who mapped the ocean floor in the 1950s.
Alexandria under the Antonine Emperors: Ptolemy’s Geography, about 150 AD
Claudius Ptolemy lived and worked in Alexandria, then a city of the Roman province of Egypt. His Geography, written in Greek around 150 AD, was a revision of a lost atlas by Marinus of Tyre. Its eight books contain a treatise on method, a gazetteer and instructions for three different projections. The gazetteer lists about 8,000 localities, the largest such database from antiquity, and roughly 6,300 of them carry latitude and longitude values so that they can be plotted on a grid.
Ptolemy measured latitude from the equator, as we still do, and set his prime meridian through the Fortunate Isles, near El Hierro in the Canary Islands, the westernmost land he knew. His maps spanned 180 degrees of longitude, from the Atlantic to China. The text outlived its maps: no Greek manuscript survives from before the 13th century, and the Byzantine monk Maximus Planudes, hunting for a copy in 1295, had to redraw the maps from the coordinates alone. A Latin translation made in Florence in 1406 or 1407 by Jacobus Angelus carried the work into Renaissance Europe, where its coordinates became the starting point for the first printed world maps.
Luoyang and the Jin Court, 267–271: Pei Xiu’s Six Principles
Pei Xiu (224–271) was a statesman of the Cao Wei state who rose under Sima Zhao and was appointed Minister of Works of the new Jin dynasty in 267. He is remembered for a preface, preserved in the 35th volume of the Book of Jin, in which he dismissed earlier Han maps as rough and unreliable and laid down six rules for making a good one: graduated divisions to fix the scale, a rectangular grid, the pacing out of right-angled triangles to derive distances that cannot be walked, and allowances for high and low ground, for angles, and for curves and straight lines.
With these principles he compiled a historical map of China in eighteen sheets, based on the ancient Yu Gong text, and presented his silk maps to Emperor Wu. None survives. Historians such as Howard Nelson argue that Pei Xiu took the grid from the astronomer Zhang Heng (78–139), and 20th-century excavations in Gansu and at Mawangdui have shown that pre-Han and Han maps were better than he allowed. His written rules, though, became the reference point for Chinese mapmakers for centuries.
Palermo, 1138–1154: al-Idrisi at the Court of Roger II
Abu Abdullah Muhammad al-Idrisi was born in Ceuta in 1100, studied in Córdoba and travelled through North Africa, al-Andalus and as far as Anatolia before accepting an invitation, around 1138, from the Norman King Roger II of Sicily. Over some fifteen years in Palermo he interviewed merchants and sailors, kept only what sources agreed on, and sent agents to check doubtful reports. His sources included Ptolemy, read in Arabic translation, and the Balkhi school of geographers founded in 10th-century Baghdad.
The result, completed in 1154 a few weeks before Roger died, was the Nuzhat al-mushtaq, known in Europe as the Tabula Rogeriana. It divided the known world into seven climatic zones, each cut into ten sections, giving 70 two-page maps with Arabic legends. South is uppermost on every sheet, Mecca lies in the middle, and a composite version was engraved on a silver disc about two metres across. The atlas shows all of Eurasia but only the northern part of Africa, and European geographers went on copying it for some three centuries.
Venice and Istanbul, 1450–1517: Fra Mauro and Piri Reis
Fra Mauro was a Camaldolese monk at the monastery of San Michele on Murano, in the Venetian lagoon. Around 1450 his workshop finished a circular world map on vellum, set in a frame 2.4 metres square, for the Signoria of Venice; a second version, completed in 1459 for King Afonso V of Portugal, has been lost. It carries about 3,000 inscriptions, puts south at the top, and breaks with medieval custom by refusing to centre the world on Jerusalem or to place the Garden of Eden on the map itself. The Venetian copy is usually displayed in the Biblioteca Nazionale Marciana and is the largest surviving map from early modern Europe.
Some sixty years later, the Ottoman admiral Piri Reis compiled a world chart in 1513 that he presented to Sultan Selim I after the conquest of Egypt in 1517. It is a portolan chart, built on compass roses and wind lines rather than latitude and longitude, with notes mostly in Ottoman Turkish. Only about a third survives, in the Topkapı Palace in Istanbul. When it was rediscovered there in 1929 it caused a stir, because its Caribbean appears to copy a lost map by Christopher Columbus. A once-popular claim that it shows an ice-free Antarctica has been disproved.
Saint-Dié, Antwerp and Duisburg, 1507–1595: Waldseemüller, Ortelius and Mercator
In April 1507 a circle of scholars at Saint-Dié in the Duchy of Lorraine, working under Duke René II, published Martin Waldseemüller’s wall map Universalis Cosmographia. Printed from twelve woodcut sheets, each about 46 by 62 centimetres, it was the first map to use the name “America”, placed on South America in honour of Amerigo Vespucci, and the first to show the new continents separated from Asia by an ocean. About a thousand copies were printed; a single copy survives, probably from a printing made after 1516. Joseph Fischer found it in 1901 at Schloss Wolfegg in Württemberg, and the Library of Congress bought it for ten million dollars. Chancellor Angela Merkel formally handed it over in Washington on 30 April 2007.
Gerardus Mercator, born Gerard de Kremer in Rupelmonde, Flanders, on 5 March 1512, trained at Leuven under Gemma Frisius. While living in Leuven he was arrested on suspicion of heresy and held for months in Rupelmonde castle before being released for lack of evidence; others on the same list were executed. In 1552 he moved to Duisburg in the Duchy of Cleves, where he spent the rest of his life. His world map of 1569, made “for the use of navigators”, introduced the projection on which a course of constant compass bearing is a straight line. It is still the basis of nautical charts, as our guide to the Mercator projection explains, along with the price it pays in distorted areas near the poles.
Abraham Ortelius of Antwerp, who had travelled with Mercator in 1560, beat him to the bound atlas. Printed on 20 May 1570, Ortelius’s Theatrum Orbis Terrarum gathered 53 maps by other cartographers in one uniform format, arranged by continent and region, with text on the back of each. It is usually counted as the first modern atlas. Mercator supplied the name: his Atlas, published in 1595, the year after his death, was the first use of the word in connection with maps. He meant it as the title of a treatise on the creation and description of the universe, named after a legendary king of Mauretania traditionally considered the first great geographer.
Paris and Madras, 1744–1871: The Cassinis and the Great Trigonometrical Survey
In 1672 Louis XIV asked the Academy of Sciences for a map of France “with the greatest precision possible”. Four generations of the Cassini family took up the task. César-François Cassini de Thury (Cassini III) began the great topographic map in 1744, and his son Jean-Dominique (Cassini IV) finished it. Its 180 plates, at a scale of 1 to 86,400, made it the first map of a whole country built on geodetic triangulation.
In India the East India Company applied the same method on a vaster scale. William Lambton measured the first baseline, 12.1 kilometres long, near Madras on 10 April 1802. George Everest, Andrew Scott Waugh and finally James Walker carried the triangle chains north until the Great Trigonometrical Survey was completed in 1871. Indian surveyors called pundits, including the cousins Nain Singh Rawat and Kishen Singh Rawat, mapped Tibet, where Europeans were barred. In 1852 the Bengali mathematician Radhanath Sikdar, working in Dehradun, was the first to identify Peak XV as the world’s highest, and in 1856 Waugh announced its height as 29,002 feet. The story of how that figure has changed since is told in our guide to how tall Mount Everest is.
Lamont Geological Observatory, New York, 1952–1977: Marie Tharp Maps the Seafloor
Marie Tharp (1920–2006), born in Ypsilanti, Michigan, joined Maurice Ewing’s Lamont Geological Observatory at Columbia University in 1948 as a draftsperson. Women were not then allowed on its research ships, so while Bruce Heezen gathered echo soundings at sea aboard the Vema, Tharp turned the data into maps. In 1952 she lined up about six sounding profiles, mostly from the research ship Atlantis, across the North Atlantic and found a V-shaped valley running continuously along the crest of the Mid-Atlantic Ridge. She read it as a rift where the seafloor was being pulled apart. Heezen dismissed the idea as “girl talk”, and it took her a year to convince him.
Because the US government restricted topographic seafloor maps during the Cold War, she and Heezen drew theirs in a pictorial style, publishing a physiographic map of the North Atlantic in 1957. Tharp went on to trace the rift into the South Atlantic, the Indian Ocean, the Arabian Sea, the Red Sea and the Gulf of Aden, evidence for a single global rift system. Her name was missing from the major plate-tectonics papers of 1959 to 1963, and in 1964 Ewing fired her after a dispute with Heezen. She kept working from home and finally went to sea herself in 1968 aboard the USNS Kane. With the Austrian painter Heinrich Berann she and Heezen produced The World Ocean Floor, published by National Geographic in 1977, and she received the society’s Hubbard Medal in 1978. The ridge she drew is the subject of our guide to the Mid-Atlantic Ridge, while the clay tablets, papyri and silk maps that came long before any of these cartographers appear in our guide to the oldest maps in history.