I also thought about it. Indeed, the point is that all merlons are of this kind. This can mean one of the two things:
1) The author depicted real-life objects with ghibelline merlons exclusively. This means, in turn, that the wall cannot be the wall of China etc. In other words, the Rosettes folio is not the map of the world.
OR
2) The ghibelline merlons were so commonplace for the author that he really did not bother about other kinds of merlons.
If we adopt the view #2, then the question arises why were the ghibelline merlons commonplace for the author, and not some other kinds of merlons? Probably, because at the time of drawing, the author lived in the place with ghibelline merlons, so his notion of commonlace merlons was shaped (at that time of his life) by those swallow-tails.
The very notion of "provenance" is somewhat unsteady in this case. In those days, learned people often travelled between various universities, abbeys and/or courts. The author may have originated from Northern Europe, or Spain, or wherever, but at the time of creation of this map he lived in some place with such merlons.
I am a bit confused though about why everyone repeats "Northern Italy" over again. As far as I know, swallow-tail merlons in 15c were observed not only in Italy, but also in the territories of modern Germany, Switzerland and Austria.
I also remember Diane arguing that this merlon shape is encountered somewhere in Persia or something like that. Either case, it is not Italy-exclusive, is it?
EDIT:
Another interesting possibility is that by depicting all merlons as ghibelline ones the author wished to implicitly declare himself as a ghibelline.
1) The author depicted real-life objects with ghibelline merlons exclusively. This means, in turn, that the wall cannot be the wall of China etc. In other words, the Rosettes folio is not the map of the world.
OR
2) The ghibelline merlons were so commonplace for the author that he really did not bother about other kinds of merlons.
If we adopt the view #2, then the question arises why were the ghibelline merlons commonplace for the author, and not some other kinds of merlons? Probably, because at the time of drawing, the author lived in the place with ghibelline merlons, so his notion of commonlace merlons was shaped (at that time of his life) by those swallow-tails.
The very notion of "provenance" is somewhat unsteady in this case. In those days, learned people often travelled between various universities, abbeys and/or courts. The author may have originated from Northern Europe, or Spain, or wherever, but at the time of creation of this map he lived in some place with such merlons.
I am a bit confused though about why everyone repeats "Northern Italy" over again. As far as I know, swallow-tail merlons in 15c were observed not only in Italy, but also in the territories of modern Germany, Switzerland and Austria.
I also remember Diane arguing that this merlon shape is encountered somewhere in Persia or something like that. Either case, it is not Italy-exclusive, is it?
EDIT:
Another interesting possibility is that by depicting all merlons as ghibelline ones the author wished to implicitly declare himself as a ghibelline.