Yeah, cause Italian, even if it’s the most direct evolution of Latin (I studied this one for 6 years), is the modernization of ancient Florentine/Tuscan dialect. Every region of Italy developed its own vulgar version of Latin. So of course many many names and words change a little bit.
Res Publica (literally, “public thing”) becomes Repubblica or Republic.
Imperium (not a form of state, but a specific kind of power) becomes Impero or Empire.
I digress too.

But I’m looking forward to this edit 😉