by Gunnar Thomspon 


The Portuguese Isle of Antillia is generally regarded as one of the “fantasy islands” of medieval mariners.  However, scientific data from 13 Atlantic charts now reveals that Portuguese navigators under Prince Henry and John II accurately determined the location of Florida by 1489.  These charts include the works of Albertin DeVirga, Andrea Bianco, Fra Mauro, Henricus Martellus, Martin Behaim, Cantino, and Caveri.  The accuracy of Portuguese maps explains the Columbus claim that he had an accurate map showing the way across the Atlantic in 1492.  His belief that the overseas mainland was The Indies resulted from a Portuguese effort to confuse commercial rivals. 


* * * * *

When 16th century historians set about writing the story of maritime exploration, they lacked many pertinent documents that would later surface.  Thus, they were hampered in their efforts to achieve accuracy by insufficient data.  They were also burdened with political and religious loyalties that led them to ignore contrary theories while extolling evidence that supported their own convictions.  In retrospect, it is therefore not surprising that the evidence of cartography runs counter to many cherished assumptions about how and when the New World came into existence as a cartographic feature on world maps.  A case in point is the isle of Antillia.  Commonly regarded as a “fantasy” by many historians, this little isle of Portuguese derivation may well prove to be the seed of New World discovery.[1] 

Antillia is the name of a mid-Atlantic isle that shows up on early 15th century Portuguese maps.  The name endured on 16th century maps and was eventually applied to the Caribbean Islands we generally call “the Antilles.”  According to legends recounted by Ferdinand Colon and summarized in captions on the Behaim globe and the Ruysch map of 1508, Antillia was a place of refuge for Christians who fled the Saracen invasion of Portugal in 714 AD.  Ferdinand mentioned that Antillia was situated 200 leagues (or about 600 miles) west of the Azores.  Antonio Galvano identified the Antilles as being equivalent to the “new isles” that Spain claimed following the Columbus expedition.[2] 

The name “Antillia” is variously interpreted as having one of the following meanings: 1) an isle “ante” or in front of Europe; 2) an isle “opposite” Tile—which was an old Roman name for Iceland (thus, ant-tile); or 3) the “ancient isle” derived from the word antiglia.  The last version occurred on some 16th century maps as an alternative name for the Antipodes (a.k.a., Mundus Novus or South America).[3] 

Figure 1 shows a typical version of Antillia as a schematic, rectilinear isle located someplace in the mid-Atlantic Ocean opposite Portugal and the Strait of Gibraltar.  Some writers such as William Babcock and Karre Prytz regard this Antillia as an early representation for the East Coast of North America.[4]  However, most modern writers tend to regard the tale of 8th century Portuguese refugees as apocryphal.  It is commonly thought that Columbus altered his course in 1492 sailing north towards the presumed location of Antillia—but found only clouds.  Since no such island actually exists 200 leagues west of the Azores, modern writers tend to lump Antillia in with a host of other “fantasy” isles that occur on medieval mappamonds or wheel maps.[5]  Accordingly, Zvi Dor-Ner dismissed the Antillia maps as irrelevant to the study of New World discovery:

“The legendary—and wholly imaginary—island of Antilia, shown in red on this 1424 map by Zuane Pizzigano, continued to show up on charts of the Atlantic even after the ocean was finally traversed…it was possibly among the islands that Columbus’s charts showed as lying on the north of his route.”[6]


Portuguese Atlantic Charts

Dor-Ner recognizes the fact that Columbus had charts of the Atlantic Ocean.  This should seem quite odd given the popular tradition that Columbus sailed boldly into a “Sea of Darkness” that was supposedly unknown to Europeans.  The Atlantic couldn’t possibly have been such a “Dark Sea” if Columbus actually had nautical charts to show him the way.  Dor-Ner is well aware that Columbus had charts of the Atlantic, and these charts played an instrumental role in the course he took across the seas in 1492.  We even have a fairly clear idea of what these charts contained in the way of nautical information.  Dor-Ner observed that:

The twenty-inch globe constructed at Nuremberg by Martin Behaim represented the last, best attempt at understanding the distributions of land and water on the earth before Columbus set out upon his enterprise.  Behaim’s globe, in fact, showed the world as Columbus believed it to be.[7]


Martin Behaim was a cartographer and German expatriate who began working in the Portuguese service in 1482 and died in 1507.  His globe of 1490-92 and the maps of his associate, Henricus Martellus Germanus (1489 & 1490), portray the opposite coast of “The Indies” (our Asia) as being 4,000 to 5,000 miles west of Europe.[8]  The actual distance is about 4,200 miles.  Modern historians generally assume that the placement of the East Coast of “The Indies” on maps by Behaim and Martellus was a coincidence caused by their underestimate of the circumference of Earth and the number of degrees allocated to the Atlantic.  Al-Farghani’s estimate of the circumference (20,400 miles) when combined with Behaim’s indication of about 90º for the expanse of the Atlantic Ocean suggested that the distance between Europe and the Indies should be about 5,000 statute miles.  Based on these figures with his own adjustments for the length of a degree at the Tropic of Cancer, Columbus estimated that the distance between the Canary Islands and Cipangu (Japan) should be about 2,400 miles and the distance to mainland about 3,400 miles.[9] 

Columbus was so convinced of the accuracy of his maps that upon reaching Cuba, he wrote in his log on October 24th, 1492: “All my globes and world maps seem to indicate that the Island of Cipangu is in this vicinity.”  He calculated that his caravels had sailed 1,142 leagues (3,426 miles) or right about where Behaim’s globe indicated the location of mainland.[10]  On November 2nd, he revised his assessment of their location by asserting that they had actually reached mainland a few hundred miles west of Cipangu. 

On Behaim’s globe, there is a great macro-peninsula called “Zaiton or Mangi Province” at the latitude of the Columbus voyage along the Tropic of Cancer.  Behaim’s globe and maps by Martellus show this macro-peninsula reaching far out into the Atlantic—making it appear to be the closest part of the mainland for European voyagers.  Figure 2 shows this macro-peninsula on the Martellus map.  Actually, there is no such peninsula at the Tropic of Cancer on the coast of Asia.  Ravenstein called this fabulous peninsula “the Horn of Asia.”[11]  It was this peninsula that Columbus believed he had found.  Thus, when natives told him there was a huge island to the east (Haiti), Columbus surmised that his map was accurate in showing a great macro-peninsula with a huge island at about the same latitude to the east. 

The Columbus Atlantic charts serve as a reminder that it was the Portuguese who undertook a comprehensive survey of the Atlantic Ocean.  Prince Henry The Navigator of Portugal (1420-1460) and later King John II sent numerous explorers west seeking the location of mainland referred to as “Antillia” or the “Isle of Seven Cities” in the 15th century.[12]  Among these Lusitanian navigators were Goncalo Cabral, Joao Fernandes, Vincent Dias, Diego de Tieve, Dom Fernao, Joao Vogado, Jao Vaz Corte-Real and sons, Ruy Concalves, Fernao Telles, Joao Affonso de Estreito, Alonso DeHuelva, Fernao Dulmo, Jacobus Carnus, Joao Coelho, and Martin Behaim—to name a few.[13] 

Did any significant knowledge of the Western Atlantic result from all these expeditions? 

We know for certain that Prince Henry’s navigators located Madeira and the Azores in the mid-Atlantic Ocean.  Although modern historians continue to argue over the significance of Portuguese expeditions farther west, there are numerous testimonials supporting the theory that Portuguese mariners succeeded in charting the coast of the North American shoreline opposite Europe.  The biographer of Columbus, Ferdinand Colon, wrote that the Portuguese had succeeded in reaching Anitllia by 1430.[14]  The Martin Behaim Globe includes a caption indicating that European ships had passed by Antillia in 1414; and the 16th century historian Antonio Galvano mentioned an ancient Portuguese report that a ship had landed at Antillia in 1447.[15]  Shortly following the return of the Columbus expedition, historian Peter Martyr surmised that the Spanish-Italian adventurer had reached isles previously known as “the Antilles:”

He (Columbus) assumed that he had found Ophir, whither Solomons’s ships sailed for gold, but the descriptions of the cosmographers well considered, it seems that both these and the other islands adjoining are the islands of Antillia.[16]


The King of Portugal, John II, and his court chronicler, Ruy De Pina, came to the same conclusion: Columbus had merely reached isles that were already known to the Portuguese as Antillia.[17] 


Early New World Cartography

The proof that King John II and his clerk were correct in their assessment of the Columbus landfall is to be found in the early cartography of Antillia and the adjacent mainland.  A comprehensive assessment of the cartographic record including some charts that have only recently come to light reveals surprising evidence of early Portuguese knowledge of New World shores reaching all the way from Newfoundland to Brazil. 

Figure 3 shows Andrea Bianco’s map of 1436 that places “Stockfis” on the southern extremity of Greenland.  This “Stockfis” (a.k.a., Stockfish, Salt Fish, or cod) is generally taken to be an early reference to the Newfoundland fishery.  This comes as no great surprise since Icelandic fishermen apparently traveled to that region often to gather cod.  What is surprising is a portrayal of the same region on a 1490 map called the “Paris Map.”  This map, Figure 4, is sometimes attributed to Columbus.  It has a group of islands called “Isles of Seven Cities” within 200 miles of the actual longitude and latitude of Newfoundland.  That is not to say that Newfoundland was The Isle of Seven Cities—for the name was variously applied to land areas from the Caribbean to the Gulf of St. Lawrence.[18]  We know from historical accounts that several Lusitanian expeditions had sailed to this region prior to 1490.  Among the few that have been identified are voyages under the command of Joao Fernandes, Jao Vaz Corte-Real, Johannes Skolp (Scolvus), and Fernao Dulmo.  Ferdinand Colon mentioned that two of his father’s associates, Fernao Dulmo and Velasco DeGalicia, had succeeded in reaching the “Baccalos” on a voyage that took place by 1486.  This “Baccalos” is a Portuguese word for codfish and is generally taken as a reference to Newfoundland.  Since Dulmo’s patent from John II specified mainland known as The Seven Cities, we have further indication of the association between Newfoundland, Baccalos, and The Seven Cities. 

Numerous 16th century cartographers (Wyfliet, Lok, Frisius) mentioned that the Skolp expedition reached the vicinity of Newfoundland or Labrador in the year 1476.[19]  Thus, we have evidence from both cartography and historical accounts that Portuguese mariners had explored and accurately determined the distance to isles and mainland in the region of Newfoundland by 1490. 

Portuguese mariners had also determined the approximate location of Florida by this point in time.  The cartographic origin of Florida can be traced back to a 1436 map (Figure 5) by Andrea Bianco.  Bianco was a Venetian cartographer who sometimes worked in the Portuguese service.[20]  Vicenzio Formaleoni argued in 1788 that Bianco’s Antillia was an early representation of America.  Although it appears to lie too close to the west coast of Portugal, some allowance can be given for the difficulty in estimating longitude in the 15th century and the tendency for cartographers to truncate areas of maps where few details were known.[21]  The close similarity of Bianco’s Antillia to a similar region of land (has antilhas) at the same latitude on the so-called “Cantino Map” of 1502 (Figure 6) reveals that the 1436 map simply gives an early approximation for the longitude.  The identification of Bianco’s Antillia with has antilhas on the Cantino Map can be determined by the same shape, same latitude, and same name. 

Bianco’s Antillia with its peculiar, macro-peninsula in the approximate shape of Florida, is only one of 13 charts that show some form of a macro-peninsula across the Atlantic from Europe.  Data from these maps showing the approximate latitude and distance west of Europe are presented in Tables I and II.


Table 1: Macro-Peninsula on Ancient Maps

author/map      date  source           lat. N  miles

Macrobius        440  Roman                       45°     ?

Sanudo          1320   Italian              45°     ?

DeVirga          1414    Ven./Fran.     polar?    ?

Yale Vinland   1440   Swiss/Fran.       38°     ?

Florentine       1447   Florence           40°     ?

Genoese         1457   Genoa             40°     ?

Florida           2000  Atlas                25°  4,200


The maps in Table I include a 15th century copy of a map by Macrobius and one example of maps by Marino Sanudo that portray mainland (India/Asia) west of Europe with a macro-peninsula above a huge gulf.[22]  None of these maps contain sufficient information to estimate the distance separating the western mainland from Europe.  However, Classical writers mentioned in Roger Bacon’s Opus Majus and Pierre D’Ailly’s Imago Mundi suggested that the sailing distance across the Atlantic was within the capabilities of ordinary mariners. 

Table II presents information on maps by Portuguese agents and cartographers.  It is immediately apparent that the Portuguese achieved a higher degree of accuracy with respect to sailing distances and latitudes indicated on their maps.  This accuracy reflects the strong association between navigators trained at Sagres under the direction of Prince Henry The Navigator and the skills of Jewish and Venetian cartographers working in the Portuguese service. 





Table II: Portuguese Macro-Peninsula/Antillia

author/map      date  source           lat. N  miles

Bianco (a)       1436   Ven./Port.        35°  1000

Bianco (b)      1436   Ven./Port.       30°   1000

Fra Mauro      1459   Ven./Port.        25°     ?

Toscanelli       1474   Flor./Port.        20°  4,500

Martellus        1489   Ger./Ven.         23°  4,000

Martellus        1490   Ger./Ven.         23°  4,000

Behaim          1492   Ger./Port.        23°  4,500

Florida           2000  Atlas                25°  4,200


The latitudes of the tip of the macro-peninsula on Portuguese charts can be estimated by comparing their locations to reference points in Europe. Eight examples are presented in Figure 6.  The existence of such a macro-peninsula across from Europe dating to at least 1414 (the date on the DeVirga map) establishes that there was a cartographic tradition for a macro-peninsula along the coast of Asia/India.  According to most historians, Medieval Europeans were completely ignorant of both the Asian coast and the North American coast—so there is no current explanation for why cartographers should have elected to portray such a macro-peninsula on their maps. 

On the other hand, if these peninsulas are examined on a temporal basis, we can determine that over time, cartographers moved the southeastern tip towards the actual coordinates of the tip of Florida at N25º Latitude about 4,200 miles west of Europe.  This general correction of the location of the macro-peninsula is presented in Figure 7.  Since this cartographic adjustment occurs during a period of known Portuguese exploration in the Western Atlantic, the possibility has to be considered that mariners sailing for John II had accurately determined the location of mainland (Florida or Antillia) prior to the Columbus expedition. 

Henricus Martellus (1489 & 1490) and Martin Behaim (1492) brought the macro-peninsula down from 35°N (the latitude of Bianco’s Antillia) to the Tropic of Cancer (23°27’N) or just a bit south of the actual latitude of Florida.  This is the kind of increasing accuracy we might expect if explorers and cartographers refined their measurements over time.  We noticed that in Table II, maps attributed to the Portuguese agents or cartographers working in their service have a particularly high degree of accuracy with regards to the latitude of Florida and the distance west of Europe.  The Bianco maps are only 5° too far north, although the longitude seems to be off by 2,500 miles.  This error could be attributed to the infancy of cartography or simply the perspective of the map and the tendency of cartographers to conserve space.  By 1489, the Martellus map shows that Portuguese mariners had determined the actual latitude for the macro-peninsula (Florida) with its tip just above the Tropic of Cancer.  It seems that Martellus and Behaim erred by approximately 200 miles in their estimates of the distance between Europe and the western mainland.  This degree of accuracy with respect to both longitude and latitude for a macro-peninsula west of Europe can not be attributed to coincidence. 

Farther south, Portuguese mariners had also determined the location of the southern continent (that Vespicci called Mundus Novus) by 1448.  In that year, a map by Andrea Bianco identifies a huge isle west of Africa with the caption: isola otinticha 1500 mia or “isle authenticated at 1500 miles.”  Since this is a fair estimate of the distance between the coast of Brazil and Cape Verde, Africa, Bianco’s map can be taken as an indication that the Portuguese had a fairly accurate idea of the location of mainland south of the Caribbean.  The fact that the caption uses the term “authenticated” instead of “discovered” suggests that navigators had succeeded in locating a mainland that was sighted on previous voyages to the southwest. 

Several accounts confirm Portuguese knowledge of this mainland.  Columbus was appraised of the existence of such a mainland in 1493 when he stopped by King John II’s royal palace in Lisbon to inform the King that he had established a shortcut to “The Indies.”  The King not only advised Columbus that the Caribbean Isles were already known as the “Antilles,” he further informed his guest that there was mainland south of the Antilles.  This was the first thing Columbus had heard of mainland in that direction as it was not indicated on any published Portuguese maps.  Based on this revelation, Columbus sailed far south of his customary route to Hispaniola in 1498 in order to ascertain what the King of Portugal had meant by mainland being located in that direction. 

Modern historians tend to regard King John II’s statement about a southern mainland as a mere prediction based on Roman legends of the Antipodes being located south of the Equator.  However the existence of Bianco’s 1448 map confirms that the Portuguese had already begun mapping the land that would later be called Mundus Novus (that is, Amerigo Vespucci’s “New World”).  Knowledge of this land apparently led Portuguese authorities to demand that the papal line of demarcation separating Spanish from Portuguese territories be moved to 370 leagues west of the Cape Verde Islands in the Treaty of Tordesillas—thus giving them access to Brazil.  The English spy, Robert Thorne informed King Henry VII in 1527 that prior to Columbus’s voyage: “The King of Portugal had already discovered certain islands that lie against Cape Verde, and also a certain part of the mainland towards the South, and called it the land of Brazil.”[23] 

One additional document pertains to early Portuguese knowledge of the southern mainland.  The Nuremberg Chronicle for 1493 includes a statement that Nuremberg expatriate Martin Behaim had sailed in company with Jacob Carnus of Portugal south of the equinotical line to the alter orbis.  This alter orbis or “Other World” was one Roman designation for the Antipodes.  It is significant in this respect that Columbus also referred to mainland he encountered near Venezuela as the alter orbis.  His brother Bartholomew (in a map dated 1506 and copied by Alessandro Zorzi) indicates that the mainland was also known as “the Antipodi” or the Antipodes of Roman legend.  Columbus subsequently encountered mainland (Paria and Veruga in that region.  He “discovered” the southern mainland in the 15th century Christian sense by conducting solemn ceremonies in order to officially confiscate native lands in the name of royal patrons. 


Revealing a “New World”

It was not until Amerigo Vespucci arrived upon the scene as a quasi-secret agent of King Ferdinand of Spain that the so-called “New World” was revealed to Europeans.  Up to that point in time, most Europeans expected to encounter some resistance in Asian waters from Arabs and the Chinese who traded with the Spice Islands.  Thus, their visions of western commerce were somewhat limited to a region already dominated by the great khan, the denizens of Gog-Magog, and the bastions of paradise.  Vespucci’s 1502 description of a New World waiting for European colonization painted an entirely different picture of opportunities in the west. 

Although several of Vespucci’s four expeditions to the West are somewhat controversial because of limited supporting evidence, the mainland and isles he claimed to have visited are fairly well delineated in the Portuguese Padrao or “King’s Map” of 1502 (Figure 9).  This map shows the emerging shoreline of Newfoundland, a huge gap of ocean where New England should be located, the Florida Peninsula, shoreline along the Gulf of Mexico between Florida and Texas, and the coast of the southern continent from Venezuela to Brazil.  Vespucci identified this southern continent as a Mundus Novus or “New World” in letters that circulated in Europe between 1502 and 1507.  Vespucci called the southern continent a “new world” because it wasn’t shown on any contemporary maps.  He added that if the southern continent was the same mainland that was known to the ancients as the Antipodes, Church authorities held that the land was uninhabited.  Therefore, it was for all practical purposes—a “New World” in the eyes of contemporary Europeans.  Vespucci’s descriptions of vast new territories that were just waiting for European expansion inflamed the passions of Renaissance entrepreneurs who were anxious to stake their claim upon new territories and new resources in the West.  Thus, Vespucci’s characterization of the mainland as a “New World” swept Europe by storm—leaving the reputation of Columbus and his erroneous claims of a “shortcut to the Indies” lying in the dust. 

Vespucci’s letters were so popular by 1507 that the German cartographer, Martin Waldseemuller, decided to dedicate a New World map proclaiming Vespucci the “discoverer of a new continent.”  Waldseemuller even named the continent “America” in honor of Amerigo—the so-called “discoverer.”  Regardless of Waldseemuller’s motives and subsequent claims on the part of Columbus supporters who want to claim due credit for their hero, we can trace the cartographic evolution of the American continent back to Bianco’s 1336 portrayal of Antillia and its macro-peninsula (Florida).  This evolution is indicated in Figure 10 where Caneri’s 1504 map shows the midway development between the Padrao of Cantino (1502) and Waldseemuller’s naming of America (1507).  Most subsequent maps of the New World continents are built upon this cartographic foundation that is often referred to as the “Lusitano-Germanic tradition.”[24] 

Historian Kenneth Nebenzahl was so impressed by the inclusion of a peninsula that looked like Florida on the Cantino and Canari maps that he called it: “the greatest unsolved cartographic puzzle of the period.”[25]  Officially, Florida wasn’t discovered until Ponce DeLeon’s expedition in search of Bimini in 1513.  However, no maps have survived from that expedition, nor was there any change to existing charts of the area—so it is impossible to say that DeLeon added anything to geographic knowledge. 


Conclusions: Discovery from the Perspective of Cartography

There appears to be little correspondence between cartographic documents and the popular version of history.  The Albertin DeVirga Map of 1414 (or 1411) is the oldest map that contains sufficient detail of New World mainland to suggest that it was based on a scientific survey.  This follows in time Roger Bacon’s 1265 proposal to make a scientific map and historic references to English Franciscans mapping Northern Europe and isles to the west.[26] 

According to the testimony of a Dutch Journalist, Jacob Cnoyen, an Oxford Franciscan presented King Edward III with a document called Inventio Fortunatae or “Discovery of The Fortunate Isles” circa 1360.  This document included measurements made using an astrolabe.[27]  Since Prince Henry The Navigator of Portugal was the great-grandson of Edward III, it is possible that knowledge of the western isles reached Henry via his English ancestors or their Venetian allies.  Since Edward III once had a navy of more than a thousand ships and the Oxford Franciscans once had a factory for making astrolabes, it seems readily apparent that the English had the capacity for mounting a scientific survey of the Western Isles. 

The Dutch account of Inventio Fortunatae along with the DeVirga map lend credence to the conclusion that English Franciscans followed by their Portuguese allies in the 15th century were principally responsible for building the foundation of scientific cartography in the West.  Amerigo Vespucci initially got the credit for “discovering” the New World because he had the audacity to reveal to the general public information that the Portuguese Kings had known for generations.  The Kings kept this knowledge secret in order to deter competition. 

Columbus was correct in his assessment that his Portuguese charts were accurate in showing shorelines of the Western Atlantic.  However, the deceptive Zaiton Peninsula that Behaim and Martellus attached to the East Coast of Asia can be regarded as an effort in commercial espionage.  Likewise, their failure to include a southern continent on Atlantic maps when the location of “Brazil” had already been established was probably done to conceal potentially lucrative resources such as brazilwood from commercial rivals. 

When 19th century historians decided to elevate Columbus to the glory of “discoverer,” they were principally motivated by religious and political convictions.  They either lacked sufficient cartographic documents or neglected to conduct a thorough analysis of the ones that were available.  The most important documents that were virtually unknown until the 20th century included: 1) the DeVirga Map which wasn’t found until 1911; 2) the Yale copy of the Martellus Map showing details of longitude and latitude; and 3) the Cantino copy of the Padrao

Contrary to traditional beliefs, the evidence of cartography supports the conclusion that it was the English and their Portuguese allies who deserve the preponderance of credit for creating scientifically verified continents out of mythical isles.  Indeed, the course of 15th century exploration depended upon the vanguard of mariners who sailed in secret to the New World and the cartographers who charted their progress. 



[1] See for example Donald Johnson, Phantom Islands of The Atlantic, New York, Avon, 1994; Raymond Ramsey, No Longer on The Map—Discovering Places that Never Were, New York, Ballantine, 1972. 

[2] William Babcock, Legendary Isles of The Atlantic, American Geographical Society, 1922, p. 72.  Antonio Galvano, The Discoveries of the World, Hakluyt Society Publications, 1st Series, Vol. 30, London, 1862, p. 72, identifies the Antilles with the isles that were later called “New Spain.” 

[3] For an example of “antiglia” for South America see the Portolan Atlas of 1508, in Babacock, 1922, fig. 8 showing the Edgerton MS 2803 of the British Museum.

[4] Babcock, 1922, pp. 72-84, and Karre Prytz, Westward Before Columbus, Oslo, Maritime Forlag, 1991, are among the proponents of Antillia representing America.  Babcock (p. 153) visualizes Antillia as Cuba; Prytz believes that Antillia represents the North American coast from Florida to the Carolinas.

[5] Babcock, 1922, p. 72. 

[6] Zvi Dor-Ner, Columbus, 1991, New York, Morrow, p. 142.

[7] Dor-Ner, 1991, 82. 

[8] See Dor-Ner, 1991, p. 79 for the respective estimates by Toscanelli and Behaim.  Kenneth Nebenzahl, Atlas of Columbus and The Great Discoveries, New York, Rand McNally, 1990, p.13, calculates the distance between Europe and Japan on maps by Martellus and Behaim at 3,500 miles or 90°.  John Harley, Maps and the Columbus Encounter, Milwaukee, Maier Press, indicates the distance at 4,250 miles.

[9] Dor-Ner, 1991, pp. 79-82. 

[10] Dor-Ner, 1991, pp. 164-165. 

[11] G.E. Ravenstein, Martin Behaim His Life and Globe, London, 1908. 

[12] Gunnar Thompson, The Friar’s Map, Seattle, Argonauts, 1996, (1996), pp. 175-244.

[13] For details of Portuguese Atlantic explorations see Henry Harrisse, The Discovery of North America, 1892; Thompson, 1996, pp. 175-244. 

[14] Babcock, 1922, pl 72 quotes Ferdinand Colon: “in the time of Henry infant of Portugal (1430), a Portuguese ship was drove by stress of weather to this island Antillia.” 

[15] Galvano, 1862, 72. 

[16] Pietro Martyr d’Anghiera, The Decades of the New World or West India, in F.A. MacNutt, trans., The Eight Decades of Peter Marthy D’Anghera, New York, 1912. 

[17] Arthur Newton, The Great Age of Discovery, Freeport, NY, Books for Libraries, 1932, p. 94. 

[18] A Portolan Atlas of 1508 has the whole of North America labeled as “Seven Cities.”  Babcock, 1922, fig. 8; Egerton Ms. 2803 in the British Museum. 

[19] Harrisse, 1892, p. 657-9; Thompson, 1996, 190-193. 

[20] Vicenzio Formaleoni, “Essai sur la marine ancienne des Venitiens,” in Babcock, 1922, pp. 148-157; and Gunnar Thompson, “The Cantino Bridge From Antillia to America,” in Information Bulletin, WAML, November, 1999. 

[21] Babcock, 1922, p. 157. 

[22] For details of these maps see Thompson, 1996. 

[23] Jack Beeching, Ed., Richard Hakluyt—Voyages & Discoveries, London, Penguin Books, 1972, p. 50. 

[24] Nebenzahl, 1990, p. 32. 

[25] Nebenzahl, 1990, p. 34.

[26] Thompson, 1996.

[27] Mercator’s documentation of Cnoyen’s account of the Franciscan survey is contained in his map of 1565. It is also found in Elizabeth Taylor, “A Letter Dated 1577 from Mercator to John Dee,” (1956) Imago Mundi, Netherlands, Vol. 13, pp. 56-68.


Key Words

Albertin DeVirga

Andrea Bianco



Florida, ancient cartography

Henricus Martellus Germanus

Inventio Fortunatae

Martin Behaim

Martin Wadseemuller

New World Discovery

Prince Henry The Navigator

South America, ancient cartography