I don't know if anyone has ever read I Claudius, the story of the historian/emperor who succeeded Caligula, but it's pretty instructive. I read it a long time ago, and am now reading Claudius the God. I particularly like a scene in the Senate right after Caligula was assassinated and they all try topping each other for patriotism and belief in "freedom." Up until 90 years before, the Senate had come up with the "watchword of the day" for guards. Then the Caesar took that away. So now, thinking they have won (and privately plotting to become the next Caesar), they dance around smashing stuff with Caligula's face on it, when the assassin marches in, Ollie North like, and says, reporting for duty. What is the watchword of the day?
They all go crazy and come up with LIBERTY.
It's a great read. It takes a long time to differentiate between so many people named the same thing (there's about five Herod's running around, for instance), but once you get past that, it's great.