Who was the second emperor of the ancient Roman Empire?

Caligula, didn't he like, marry his sister, make his horse a senator? What's a small thing like murder to a guy who thinks like THAT?

deosIAM, He was a Pip. His personal guards killed him, he was so revolting. He killed his sister so she couldn't have his baby. His uncle Claudius followed him, a shy man that stuttered. Claudius was a good man, just didn't live very long. I watched a PBS series "I Claudius " that I remember most of this from.