Is the locative used with multi-part city names?

Question

The Duolingo Latin course mentions New York a lot. (I'd rather have it focused on the geography of ancient Italy than the modern US, but that's beside the point now.) The locative comes up regularly: Novi Eboraci is "in New York".

But did the Romans really use locatives in the usual way when the city name consisted of several part, like a noun and an adjective? Such names might not have been all that common, but at least Carthago Nova comes to mind. If such city names do not exist at all or in sufficient numbers to draw any conclusions, I will be satisfied with that answer too.

As far as I know, the locative is impossible when the city comes with an attribute (e.g. Caesar in magna Roma vixit), but here I am looking for cases where the adjective is an integral part of the city name itself.

Answer 1

I've just started researching the topic because of your question, so this post is very much a work in progress and should not be treated as a definite answer, just a collection of information that I've come across that I think may be relevant.

My impression so far is that examples exist, but not enough to make clear generalizations.

A two-word phrase can sometimes take locative inflection

Apparently certain special types of modified nouns can appear in the locative case. I have found sources that mention the use of locative case for nouns modified by either genitive nouns or possessive adjectives:

489. The locative domi may be modified only by a possessive adjective or by a noun in the genitive; when it would be otherwise modified, the ablative with in is used instead.

     domī meae, at my house
     Caesaris domī, at Caesar's house
     in Mārcī splendidā domō, at the fine home of Marcus

(Concise Latin Grammar, by Benjamin Leonard D'Ooge, 1921, p. 215)

Given the existence of the "domi meae" construction, I don't know of an a priori reason to rule out the two-part use of the locative case in Novi Eboraci as completely impossible.

There might be some examples of city names containing adjectives taking locative inflection

There doesn't seem to be great attestation of historical usage, but some examples are mentioned in the following Textkit Greek and Latin Forums thread: novo eboraco?, by metrodorus, Mon Jul 14, 2008 9:19 pm.

The first post says that metrodorus asked Dexter Hoyos about this usage, and received a reply that cited a mixture of usages: "Teani Apuli", "Suessae Auruncae natum", and "Carthagini Novae" but also "Carthagine Nova".

The ablative could possibly be used in this context

There is precedent for the use of the ablative form for the city name Longa Alba/Alba Longa:

3. Ablative for the Locative.—Instead of the Locative in names of towns the Ablative is used, with or without a preposition—
   1) When the proper noun is qualified by an adjective or adjective pronoun: In ipsā Alexandrīā, in Alexandria itself. Cic. Longā Albā, at Alba Longa. Verg.

(Latin Grammar, by Albert Harkness, revised edition of 1881)

Answer 2

I couldn't find any city names in specific, though this Wikipedia article on Rapidum mentions a road named Nova Praetentura that had the name in the first century C.E.

Constantine also named Constantinople Nova Roma, although this was the 4th century and Constantine, so I'm not sure if you could consider it Roman in the classic sense. It also wasn't ever officially named that, but I suppose it still shows this kind of usage either way.

By the way, this question is interesting to me personally because it relates to a personal project I'm working on.