Good and Bad Emperors

Arguably and quality and character of the emperors declined steadily after Augustus. How would you account for this? How is it possible that Rome lasted as a powerful empire with rulers such as Caligula and Nero?

All the Caesars had some sort of vice they tried to hide. Was it power that fed their vice, or the vices that got them into power? Many Caesars did great public service and executed big projects, including temples and aqueducts, while others did nothing. Did civil engineering play a part in popularity or was it better to just do without and save money? The Julio-Claudians seem to be execrable men. Why do you think the Romans tolerated them for as long as they did?

Claudius was often portrayed as a fool in the Roman courts as well as by the general populace.
Why was he deified? Is he thought of as being good because he served between Caligula and
Nero, and he was better by comparison?

How do you interpret the accession of Claudius? Was it chance, as the tradition holds? Are there reasons to be skeptical about the quality of our sources for these crucial events? Compare and contrast the accounts of Suetonius with that of Josephus.

Please CITE your evidence! Each initial response must contain ONE ancient citation.