Well all the movies have some real-life characteristics sprinkled through them. Johnny Fontane was modeled after Frank Sinatra, Hyman Roth after Meyer Lansky, etc.

I'm sure the comparisons to some of the Vatican conspiracies in GFIII is not a coincidence.

And while these Vatican conspiracies haven't been proven true, I don't doubt for a minute that they are true. And I sure as hell wouldn't dismiss them as impossible.

I believe the Vatican and the Catholic Church to be one of the most corrupt institutions on Earth.