Claudius Clavus

Wikipedia:

Claudius Clavus (Suartho) also known as Nicholas Niger, (Danish: Claudius Claussøn Swart), (born 14 September 1388), was a Danish geographer sometimes considered to be the first Nordic cartographer.

. . .In 1412–13 at the age of 25 he started to travel around Europe and appeared eleven years later (1423–24) in Rome. It is believed he travelled as far north as the 70°10′ N. lat. In Rome he became friends with the cardinal Giordano Orsini and the pope’s secretary Gian Francesco Poggio Bracciolini, who were among those working to update the old Roman cartography. Claudius contributed to a more realistic description of Nordic countries, in particular Iceland and Greenland, and was probably the first cartographer to put Greenland on a map. He is also known for having named Greenlandic places by using lyrics from old folk songs.

An excerpt from, “Claudius Clavus and the Early Geography of the North” By Edward Heawood, The Geographical Journal, December 2010:

It must not be thought that because Clavus could thus trifle on occasion, his work was anything but a remarkable contribution to the knowledge of the far north in his time. It is, in fact, one of the most notable geographical productions of the age before Columbus, and the authors have done good service in setting clearly forth his claims to distinction on this score. In the latter part of the work they enter fully into the sources of his information, and show that while building to a slight extent on Ptolemy, he drew mainly upon his personal knowledge of northern countries, as well as on the best northern sources then available. The extent of his first-hand knowledge is a question of much interest, especially as regards his claim to have himself visited Greenland. After full consideration the authors conclude that the claim can be made good.

An excerpt from, “How The Northern Countries Were Perceived From Ptolemy To Clavus Part 2″ By ourseafarersblog, March 11, 2016:

The Dane Claudius Clavus (born 1388) drew up a map of the north in 1427. The original was lost until 1886, when it was found in company with a Ptolemaic manuscript. It is now kept in the Nancy City Library in France. Clavus’ view of the north was better than those of his predecessors in many respects. Scandinavia was no longer depicted as a group of islands but as a peninsula, and Greenland and Iceland are included. But there were also some mistakes. Clavus connected Greenland to northern Russia and, in so doing, closed off the Northeast Passage. The extension of Asia far into the northwest perhaps has its origins in the Vikings’ misunderstanding of the edge of the pack ice or in their observations of Novaya Zemlya, possibly even of Spitsbergen. Norse men had in fact been sailing these waters 300 years before Clavus’ time. All in all, however, Clavus’ map was a valuable addition to our geographical knowledge of the north.