In Cecil’s 2006 column on whether old maps really said “Here Be Dragons”, he mentioned that the only known example of the phrase was on the Lenox Globe from the early 16th century, the text of which was published in an article in 1879. {Link} The wikipedia entry on the Lenox Globe, which includes a link to a rather murky photo, provides more information.
What Cecil’s column neglected to address, however, was the crucial question that if the phrase “Here be dragons” was only used in a cartographic context once in the early 1500’s, when did the idea that the phrase was common on medieval charts become an enduring historical myth?
The lovely people at MapHist provide some clues, along with a list of similar “Here be…” notations on old maps and charts: it appears that the phrase entered the common lexicon sometime between 1879, with the publication of the first scholarly article on the globe in the Magazine of American History, and 1928, when the phrase “Hic dragones” appears on an old map in the Dorothy Sayers story “The Learned Adventure Of the Dragon’s Head”. {Link}
But Dorothy Sayers must have got the phrase from somewhere herself: what we need now is a citation of a non-scholarly usage before 1928…