I'll start off with "The Holy Roman Empire is neither Holy, nor Roman, nor an Empire." Voltaire has wrecked generations of interesting discussion on a truly unique beast with that stupid one-liner that, besides its severe accuracy problems, also serves to dismiss the topic the second it comes up.
Very true about the Holy Roman Empire. It was simply a political term for the Catholic Church at its peak. The very first thing we learned in our History of the Middle Ages was that it wasn't Holy, Roman, or an Empire.
