The history of emperors and monarchs is a history of blood. Henry VIII was Hitler if you were catholic. The Ceasars were Hitlers if you were just about anybody but a Roman. The Pope was Hitler if you were Galileo. Robespierre was Hitler if you happened to get renounced in late 18th century France. Sheridan, Custer, et al were Hitler if you were native american.
Truth is, Hitler wasn't all the unusual. He just caught the century off-guard at a time when it had fooled itself into thinking the human race had gotten such stuff out of its system (at least that's what we thought in the Western Democracies). Then came Hitler, Stalin, Mao, Teng, Amin, Pol-Pot, Milosevic, Shah Pavli, Hassan Assad, Kissinger, and the rest of the usual suspects. We want to believe that Hitler represents some kind of anomaly because that way we can dismiss his kind as defeated.
T'were that it were (sigh).