Thanks - I read the article.
By design he doesn't address the issue of what the "
campgate" coins depict, but rather the origin of the iconography being
provincial city gate/wall
types. However, if this is the origin of this
type of depiction, and given how widespread these
types were, maybe it does suggest that the "
campgate"
type designs might in fact either be depicting
city gates and/or interpreted that way regardless.
Incidentally, there's a website dedicated to these citygate
type provincials here:
https://citygate.ancients.info/The article gives a pretty comprehensive listing of all the imperial
campgates types, starting with the tetrarchic
argentei, but he does seem to have missed one unusual one - the
VIRTVS MILITVM type from
Cyzicus which features a portcullis as
part of the design (see example below).
The
Rome P-R specimen above, with colums (fancy ones - spirally fluted), and the
Cyzicus type with portcullis might both support the idea that these citygate-inspired designs are in fact citygates, rather than
campgates. From what I've been reading, columns like that would seem very much out of place on a
fort, as would a portcullis (given the rather proscribed layout of a typical
fort), whereas portcullis's are known to have been used as
part of some
Roman cities (e.g. Pompeii's) defenses.
Given that the purpose of coin designs was basically propaganda, it stands to reason that the public might be more impressed and concerned about their own safety than that of the army, which would be another reason to assume it a city's defences being depicted. Of course the overall message was of public
security, so pairing the design with a
legend giving a nod to the army (
VIRTVS AVGG,
VIRTVS MILITVM) was just as appropriate as giving the credit to the emperor (
PROVIDENTIAE AVGG).
Unlike the
provincial citygate
types which acurately depicted a specific city, the
campgates are for the most
part generic - a simple cookie-cutter design issued from all mints, and therefore depict a generic gate/wall rather than a specific one. The
Rome one above, with it's columns, might be an exception, or just as likely a generic depiction of any fancy
city gate rather than one in particular. Below is a slightly better researched picture of an original
Roman city gate with columns - this one from the city of
Jerash in modern Jordan.
Ben