This article in The Economist reports that a 14th century Italian monk wrote about the Norse explorations of "Marckalada" some 150 years before Columbus crossed the Atlantic.
The present day researcher who discovered the text speculates that the monk, Galvano Fiamma, likely heard of Markland from sailors in Genoa, where the Dominican once studied. The author of The Economist article concludes by writing the following:
The Dominican was scrupulous in citing his sources. Most were literary. But, unusually, he ascribed his description of Marckalada to the oral testimony of “sailors who frequent the seas of Denmark and Norway”.
Mr Chiesa believes their accounts were probably passed on to Galvano by seafarers in Genoa, the nearest port to Milan and the city in which the Dominican monk is most likely to have studied for his doctorate.
His thesis raises a new question: why does the eastern seaboard of America not feature on any known Genoese map of the period? But it could help explain why Columbus, a Genoese, was prepared to set off across what most contemporaries considered a landless void.
How likely is it that Columbus could have heard rumors of the Americas from Genoese sailors, and were such rumors commonplace?
In short, not so likely (or very unlikely) at least during his childhood in Genoa - it would have been more natural for him to hear of a possible land west to Iceland or Greenland later in his carrier by way of some English or German sailors or even those who had worked with them if he had really heard of it before 1492, aside from his disputed/ alleged voyage to Iceland in 1477.
First of all, it is not the 'first discovery' of the alleged medieval Italian text that narrates their exploration of the North Atlantic Isles based on the Old Norse information. To give an example, The following one is now regarded by most scholars as post-Columbian fake or mostly fabrication and almost no one pay serious attention to the work:
The following posts below (either answered by /u/Platypuskeeper, /u/epicyclorama and mine), are mainly relevant to OP's question:
The summary of the discussions is as following:
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On the other hand, The academic essay in question cited in the linked Economist is the following one, and it certainly looks interesting (if it really an authentic one - I assume almost every researchers on medieval Scandinavia or the Vikings take this kind of 'discovery' with a grain of salt or are very skeptical at a first glance): Chiesa, Paolo. "Marckalada: The First Mention of America in the Mediterranean Area (c. 1340)". Terrae Incognitae 53:2 (2021): 88-106. https://doi.org/10.1080/00822884.2021.1943792
Thank you for making a notice to this academic article.
He cites the translated passage of hither to unpublished medieval Latin chronicle, Chronica universalis by Italian Dominican mendicant, Galvaneus (Galvano in Italian) Flamma (d. 1345?) as following:
"Sailors who frequent the seas of Denmark and Norway say that northwards, beyond Norway, there is Iceland; further ahead there is an island named Grolandia, where the Polar Star remains behind you, toward the south. The governor of this island is a bishop. In this land, there is neither wheat nor wine nor fruit; people live on milk, meat, and fish. They dwell in subterranean houses and do not venture to speak loudly or to make any noise, for fear that wild animals hear and devour them. There live huge white bears, which swim in the sea and bring shipwrecked sailors to the shore. There live white falcons capable of great flights, which are sent to the emperor of Katai. Further westwards there is another land, named Marckalada, where giants live; in this land, there are buildings with such huge slabs of stone that nobody could build with them, except huge giants. There are also green trees, animals and a great quantity of birds. However, no sailor was ever able to know anything for sure about this land or about its features (Chronica universalis III-275, in Chiesa 2021: 92f.)."
I'd dare to say that the source identification of these passages by the author [Chiesa] is not flawless. To give some examples, both the bishop's rule and falcons had already been alluded in Gerald of Wales's Topography of Ireland, though it is on Iceland, not Greenland in this text. On the other hand, I'm almost certainly sure that Galvaneus-Galvano was not the first medieval Italian who knew so much about the North Atlantic Isles - in fact, Emperor Frederick II (d. 1250, whose mother was Sicilian and he stayed about two of third in his life south to Alps) also writes Iceland, Greenland and their falcons (gyrfalcons and white ones) in his famous treatise on falconry, Ars venandi cum avibus, though not on Marcklanda and its giants. Both descriptions of Gerald and Frederick II on Iceland and Greenland are fairly popular among specialists (at least I hope so), and both are also mentioned in my answers in the second question thread linked above.
Emperor Frederick II (or should be called as Federico II in Italian here?) is also known to have a polar bear, given to him by King Håkon IV of Norway. In turn, he presented the bear further to the sultan of Mamluk Egypt, Al-Kamil (Oleson 1950: 54). As I mentioned before in In the television show Vikings, various Medieval European courts and nobles are pictured as having a variety of rare or exotic animals such as monkeys and parrots......., exotic animals and birds were highly valued among medieval Islamic rulers, and Frederick who had grown up in her motherly side's royal court in Sicily was also familiar with they way of courtly life. I suppose Frederick might have in fact been familiar with almost all details of the hearsay on the North Atlantic Isles mentioned here, aside from the Markland passage.
As for giants in the Arctic and here located in Markland, the closest account is found in Historia Norvegie, written probably in the 3rd quarter of the 12th century by an anonymous Norwegian as following:
"However, when certain shipmen were trying to return to Norway from Iceland, they were driven by contrary tempests into the wintry region and at last made land between the Greenlanders and the Bjarmians [inhabitants of now Kola Peninsula] where, so they claimed, they found men of prodigious size and a country of maidens (these are said to conceive children by a drink of water). Greenland is cut off from these by icy crags......(The translated text is taken from Kunin & Phelpstead trans. 2001: 2.f)"
So, overall, the basic line of the accounts in Galvaneus (Galvano)'s hand writings seems to correspond well with the known accounts of Iceland and Greenland in the 13th century non-Scandinavian Europe, except for Markland passage in question. It sounds certainly too good to be authentic one, however (if I really had to make up a fake pre-Columbian document based on the extant medieval texts, I would also follow the content of this text up to 80%).
In the last part of this post, I list some of my reasoning of reservation/ suspicion.
'Sailors who frequent the seas of Denmark and Norway.....'
The Genoese merchants had certainly established a regular sea route to Brugge, the economic center in North-Western Europe as well as their settlement there in the end of the 13th century. It is also true that a few Italian merchants (I'm not so sure about which city they had come from, though) accompanied the papal tax collectors to get the payment of the Crusader tax from Scandinavian church provinces in the 13th and 14th century, including the payment from Greenland by way of Norway. It should be emphasized here, however, that they could finish most of their business in Brugge where the Norwegians and Germans also regularly took a visit, rather visit in Scandinavia or in the North Atlantic in person, in contrast to their fellows' wool business in England (a commercial handbook from 14th century Florence mention the detailed account of wool productions in England) (Cf. Despy 1952).
Italian sailors would also have little incentive to remember the possible new land unless it produces many exotic animals and birds, as mentioned in the cited passages above, but it is the only text that specify them as the product of Markland. It could certainly explain their apparent interest, but all the other (known) Icelandic texts allude only to the forest, not even giants and stone works in Markland.
So, while it sounds interesting, I'd recommend to wait at least for a while to accept whether the account of these passages can be accepted as authentic after the further investigation of the textual or manuscript studies.
Additional References:
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