How common is it for urban legends from a very specific location to spread?

[Morwen Edhelwen]

I'm not sure how to actually phrase the question I want to ask so I hope that this thread title isn't too vague.

Background: Not too long ago I was googling search terms for something and found this PDF of an essay written by Einar Ólafur Sveinsson in the 1930s about Icelandic folk tales and their origins. As I've got an interest in Icelandic and Norse folk tales and sagas and Norse mythology, I read it and found it quite fascinating.

One of the stories Einar discusses is told here. In a nutshell, the story goes like this: Loftur, a young boy attending the cathedral school at Hólar in North Iceland in the 18th century, was fascinated by and naturally gifted at magic and sorcery. He and a group of classmates, including two brothers named Einar and Jóhann, learned magic and made plans to obtain a grimoire called Rauðskinna which was rumoured to contain spells that would enable someone to control the Devil, and the attempt not only failed but eventually led to Loftur losing his mind and then his life.

The essay goes into detail about the sources for the story so I'm quoting the parts that relate to the question.

The centrepiece of G’ísli [Konráðsson's] narrative is Loftur's attempt to get hold of the book of magic. "It was common knowledge", he says that a
certain magician was buried in Hó—lar churchyard" and that the manual
Grey vellum ("named Red vellum by others",) which was
bigger than any other book of magic, was buried with him. "Loftur
thought night and day of getting hold of the book, and spent three
nights waking up the dead from the churchyard; he raised a great crowd,
but the book did not appear.

It was said that Loftur pursued his search
so far as to make a contract with the Devil. ÔHe did this right inside the
dormitory, and some of the schoolboys believed right up until the
closure of the school (1802) that his footprints as deep as the ankles
could constantly be seen in the dormitory floor\


G’ísli's account has a half-historical air about it. contemporaries correctly. Yet the story is not a little mingled with folk story motifs...Gí’sli
states that the Rev. PŽétur [Pétursson] heard the conjuration story at school, and the
Galdra-Loftur story really is one of the best examples extant of a schoolboy
story. It must have developed in Hó—lar School by motifs from
earlier stories of magicians becoming attached to this pupil on account
of some actual incidents the nature of which cannot now be
known for sure.

So the original story was apparently an urban legend attached to a particular location (Hólar Cathedral School) told by students there to other students as a true story ("Don't believe me? He slept here, and look there are his footprints on the floor from where he made his deal with the devil!") which spread through the local district and eventually all over Iceland. The fact that Iceland has a pretty small population probably plays a big part in how welkl-known the story is, but I'm thinking generally.

So in general how common is it for an urban legend with a specific origin in a particular place to spread all over a country and become one of those stories that virtually everybody in a particular country knows? Somehow I think it would be much easier because of how widespread the Internet is.

Hope the question is clear.