Charting the Northwest Passage:
Just Turn Right at Greenland

It is no wonder Europeans tried so hard to find the elusive Northwest Passage. Cartographers had been placing it on maps and charts from the beginning. The Babylonians thought there was a ring of water around the ecumene [known inhabited world].

Map of Assyria, Babylon, and Armenia, Courtesy of the British Museum, c500 BCE.(1)

Eratosthenes, in 194 BCE, described a world surrounded by the Ocean.

Conjectured map of the Ecumene from the writings of Eratosthenes of Cyrene, Alexandria, Egypt, 194 BCE.

No one promised Medieval mariners that a voyage through the Northwest Passage would be easy. The Phoenicians sailed the North Atlantic as far as Thule [Iceland]. It is possible they ventured to Greenland or Baffin Island. They traveled far enough to learn that the North Atlantic was cold, and that winter days were short.

As described earlier, when the Etruscans and Phoenicians controlled the Pillars of Hercules [Strait of Gibraltar], they spread rumors that the Atlantic was full of sea monsters. They declared that when a ship sailed beyond the Tin Islands(2), the Hebrides(3), the Orkneys(4), and Caledonia [Scotland], “the seas became sluggish and congealed”? In fact, some ancient maps named the North Atlantic the Hyperborean Ocean or Cronius, which meant Congealed Sea or Dead Sea.

Strabo, in 24 CE, wrote that the northern islands were “inhabited by savages who lived miserably on account of the cold.” In 70 CE, Pliny wrote, “This part of the world [the seas northeast of England] is accursed by nature and shrouded in thick darkness. It produces nothing else but frost and is the chilly hiding place of the north wind.”

But this did not dissuade the Vikings, who, between 900 and 1000 CE, crossed the dark and cold Atlantic to plant colonies in Greenland, Newfoundland, and maybe Cape Cod.

In 1410, Pierre d’Ailly, the French prelate, cardinal, and scholar whose advice Christopher Columbus relied upon, wrote: “Beyond Thule, the last island of the Ocean, after one day’s sail the sea is frozen and stiff. At the Poles there live great ghosts and ferocious beasts, the enemies of Man. Water abounds there, because those places are cold, and cold multiplies humors [vapors].”

On the other hand, some scientists claimed that salt water could not freeze. Therefore, there would be no obstacles to block a ship from sailing in the polar seas other than a sea monster or two. [Some early mariners thought icebergs were sea serpents.]

Even maps drawn of a flat Earth indicated that the seas west of Europe continued northward, promising an open waterway. On the portolani drawn by the Venetian cartographer brothers Domenico and Franceso Pizigano, the northern sea flows off the edge of the map. [You have to squint to read the vague outlines of Europe on this map. The Mediterranean Sea is in the middle with the boot of Italy almost dead center.]

Domenico and Francesco Pizigano, Pizigani Portolan, Venice, 1367,(5)

During that same decade [1360s], a survey was carried out for King Edward III of England, who was, apparently, investigating the possibility of claiming and exploiting the northern islands that the Vikings had since abandoned. Norwegian records from that period include surveys of Greenland. The actual report, titled Inventio Fortunata [Fortunate Discovery], of which there were probably very few copies made, disappeared altogether by 1474. The last reference to it by someone who actually saw the document was made by Paolo Toscanelli of Florence, when he wrote a letter that year to King Afonso V of Portugal. As noted in Crossing the Ocean Sea, Toscanelli suggested the best way for the Portuguese to reach the Far East was by sailing west across the Ocean Sea. But a family squabble distracted King Afonso from following up that lead.

The portolani of Western Europe that Zuane Pizigano drew in 1424 also shows the ocean flowing to infinity off the north and western edges of the parchment.

Portolan chart by Zuane Pizigano, 1424.(6)

Greenland or Groenland

Greenland was no secret to European mapmakers in the 1450s. As we illustrated in Crossing the Ocean Sea, Newfoundland was probably no secret either. In 1457 an anonymous cartographer in Genoa, Italy, drew a map on which, some historians claim(7), a peninsula above Scandinavia was named Grinland. With no first-hand accounts of lands in the Polar Seas, it appears that Italian cartographers thought that the lands claimed by the Vikings were an extension of Scandinavia.

Genoese Mappa Map, unknown Italian mapmaker, Genoa, 1457.(8)

In 1474, when Paolo Toscanelli wrote to King Afonso V, he included a map that revealed a Northwest Passage. The map has disappeared, but historians conjecture from other data that it looked something like this and was based on the information Toscanelli derived from Inventio Fortunata.

Based on Toscanelli’s map, German cartographer Martin Behaim of Nüremberg built a globe that he named Erdapfel [Apple] in 1492. Behaim showed only water at the North Pole and promised no obstructions to ships.

Martin Behaim’s Erdapfel [Apple] globe, Nüremberg, 1492.(9)

Henricus Martellus’ map of the world, drawn at about the same time, gave a thumbs up to ships trying to sail north of the continents.

Henricus Martellus Germanus, Florence, The Yale Version of a Map of the World, c1491.(10)

Whirlpools in the Arctic or Polar Seas

In 1508, Dutch explorer Johannes Ruysch(11), referencing Inventio Fortunate, wrote, “It is said in the book concerning the fortunate discovery that at the arctic pole there is a high magnetic rock, thirty-three German miles in circumference.”

The concept of there being a magnetic mountain on the north pole started during Roman Times. Inventio Fortunata added to that by saying that the mountain was surrounded by a gigantic whirlpool and four continents. “A surging sea surrounds this rock, as if the water were discharged downward from a vase through an opening. Around it are islands, two of which are inhabited.”

In 1520, German cartographer Johannes Schöner (1477-1547) created a globe that reflects the description of the North Pole in Inventio Fortunata. Schöner drew a strait around the Circulus Arcticus [Arctic Circle] separating North America and Asia from a northern-most landmass at the North Pole, like a moat around an island.

Johannes Schöner’s Globe, Germany, 1520. (12)

Flemish cartographer Gerard Mercator perpetuated the myth of the whirlpools and the four continents when in 1569 he wrote, “The four canals … flow with such current to the inner whirlpool, that if vessels once enter they cannot be driven back by wind.”

We know Mercator was influenced by the information in Inventio Fortunata because he wrote about it in a letter to English astronomer John Dee. Even after Martin Frobisher’s exploration of the North Atlantic between 1575 and 1578, and Sir Humphrey Gilbert’s expedition in 1583 [stories coming up], Mercator, in 1595, drew a map of the north pole using the Inventio Fortunata description from c1365, two hundred years earlier. His map, shown below, gives us a clear view of where the explorers we will be telling you about thought they were headed.

Gerardus Mercator's Arctic Ocean, Septentrionalium Terrarum, 1595.(13)

Below is a comparison between Mercator’s version of the North Pole and the pole as Google displays it in 2016. The Latin term pars in early mapmaking noted a partial indication of a landmass.

Author’s tracing of Gerard Mercator’s map of the North Pole, 1595, and Google Map of the North Pole, 2014

This is how it was in 1524, when the French king Francis, commissioned Giovanni Verrazzano to find the Northwest Passage. Verrazano had no reason to think the waterway did not exist. And he probably feared what he would find once he got there.

Next Article: 1524 Giovanni Verrazzano Explores the East Coast of North America


  1. Map of Assyria, Babylon, and Armenia, Courtesy of the British Museum, c500 BCE. {{PD-Old}} Map in the Public Domain in the USA and Europe, older than 100 years. Image source:
  2. The Tin Islands included England, Ireland, and Thule [Iceland].
  3. The Hebrides is an archipelago west of northern Scotland.
  4. The Orkney Islands are east of Scotland.
  5. Pizigani [Pizzigano], Domenico and Francesco. World Map, held in the Biblioteca Palatina of Parma (Ms.Parm.1612), 1367. {{PD-old}} Public Domain. Image source:
  6. Zuane Pizzigano, Venice, 1424. {{PD-old}} Public Domain. Image source:
  7. Our arrow points to the peninsula above Scandinavia, however, we cannot read this map ourselves, so we do not know if it really says Grinland.
  8. Genoese Mappa Mundi, Anonymous Italian mapmaker, Genoa, Italy, 1457 - {{PD-Old}} Public Domain, Wikipedia, Image source:
  9. Behaim, Martin, Erdapfel [Apple] Globe. Reproduction of the globe created by Martin Behaim, Encyclopedia Larousse Illustree - 1898 derivative work. Globe created 1492. {{PD-old}} Public domain. Image source:
  10. Henricus Martellus, Yale Map, c1491, Housed in the Beinecke Library, Yale University. {{PD-Old}} Image older than 100 years and in the Public Domain. Image source (and additional information):
  11. Johannes Ruysch’s document, Universalior cogniti orbis tabula, from 1508, featured a marginal note mentioning the Inventio Fortunata.

  12. Schöner, Johannes. Globe, Germany, 1520. {{PD-old}} Public domain for USA and Germany. Image source:öner_globe#mediaviewer/
  13. Gerardus Mercator's Arctic "Septentrionalium Terrarum description,” 1595, first state from his posthumously published atlas, Atlantis pars altera.
    Image source: