Do the Romans and Greeks still believe in many Gods? You are referring to empires that have since fallen away. I believe Italy's predominant religion is Christianity now. I'm not religious so I do not actually know.
I think that monotheism is the general practice around the world though I am sure that some groups still believe in many gods - Hinduism I think?
Anyway, I was just trying to pose a question to see if it would lead to anything deeper.