By the middle of the 16th century the world map by Fra Mauro (active ca. 1430-ca. 1459/1464) was considered one of the wonders of Venice. As early as the end of the previous century, in 1483, a German preacher on his way to the Holy Land had described the beauty of the map in his travel diary after visiting the San Michele monastery in Venice. The humanist Giovanni Battista Ramusio (1485-1557), Secretary of the Venetian Council of Ten, wrote that a visit to see the map was a common stop for visitors to Venice who went to see the glassworks in Murano.
One possible motive for the admiration aroused by the large San Michele map might have been the fact that it was believed to be a copy of a lost world map by Marco Polo (1254-ca. 1324). Ramusio makes this claim in the second volume of his Navigationi et Viaggi (Navigations and Voyages), published in 1559, which includes the great Venetian explorer’s Milione among other accounts of distant voyages.
According to Ramusio, Marco Polo had returned to Venice with a nautical chart and a world map, which he had added to continuously during his travels. On the basis of those maps, a lay brother at San Michele, whose name had long since been forgotten, had painted a gorgeous illustrated map, but had ruined the cartographic value of Marco Polo’s map by adding in descriptive texts, images of animals, and other “foolishness”, as Ramusio put it, such as to compromise the quality of the authoritative original.