In the year 1532 Jacob Ziegler published in Strasbourg a book that deals primarly with the countries of the eastern Mediterranean but includes a chapter on the Northern Countries. One of the eight maps in the book shows the countries around the Baltic and North Atlantic. Ziegler's Iceland bears a considerable resemblance to the Thule of Ptolemy as regards shape and proportions, though the country has been given a new position and an improved outline. Ziegler appears to have been Sebastian Münster's principal authority for everything to do with Iceland when the latter made his world map and his map of the North for the Basel editions of Ptolemy of 1540 and 1542. Through Münster, Ziegler's type of Iceland found its way into various Italian editions of Ptolemy. Münster's Ptolemy was published in Italian translation for the first time in 1548. The book was accompanied with 60 maps by the Venetian cartographer, Giacomo Gastaldi, most made after Münster's maps. It is surprising that Gastaldi used Münster as a model but not Carta Marina of Olaus Magnus which had appeared nine years earlier in Venice. Gastaldi made a big mistake when he drew the map, the name Islandia and the names of the Icelandic sees are both on Iceland and Greenland! Greenland therefore becomes Iceland's double.
In 1561 Vincento Valgrisi published in Venice a new edition of Ptolemy's Geography, still accompanied by the maps of Gastaldi but now they had been engraved again and corrected in some places. The name Islandia has been removed of Greenland but the names of the Icelandic sees still stand there.