I once heard/read (don’t recall where) that Latin is a “constructed” or “invented” language. According to what I heard the early Catholic Church, recognizing that the meanings of words change over time, invented Latin for the express purpose of being the language of scripture. Latin would be used strictly for scripture - not for conversation. Thus would the words of scripture be made safe from changes in meaning.
More recently, I’ve heard that the Romans spoke Latin. (Of course, I’ve also heard that Greek was the common language of the Romans - this is borne out by the fact of Paul using Greek in his letters to various churches in the Roman Empire.) The idea that the Catholic Church invented Latin is rather blatantly discredited by the Biblical account of the crucifixion of Jesus: the sign they tacked over his head was written in three languages, one of which was Latin. This would have been well before the establishment of the Catholic Church.
So what’s the Straight Dope? Whence came Latin?