Capitalization in Titles of Works

Q. What is the proper way of capitalizing foreign titles appearing at the end of English titles and subtitles? For example, hypothetically, should it be “Aeneas Traveling Noctis per umbram” or “Aeneas Traveling Noctis per Umbram”? Headline style seems to conflict with Chicago recommendations for foreign titles. There doesn’t seem to be any advice for melding the two, as far as I can tell.

A. The sentence-cased Latin title fits Chicago style more neatly, but the headline caps aren’t wrong. (When it’s difficult to find an answer to a question like this, you can be fairly confident that there isn’t a single “proper” way to do it.)