Post History

If this is a formal academic work, there is likely a style guide which addresses this, or an editor who has final say.

If not, adopt a convention and explain it the first time you bring in a translation:

Original text is quoted. My translation appears in italics. When I rely on another's translation, it is in italics and a credit will appear afterwards.

"Illegitimi non carborundum"

_Don't [allow] bastards to wear you down._ This is a World War II-era example of dog Latin.