Claudius the God
Graves wrote his two-part historical-fiction series as an autobiography from Claudius’s point of view so the book is as much psychology as history in that we see how Claudius justifies himself to himself. Actions that his subjects view as blood-thirsty and tyrannical, he views as necessary and just—really, what any reasonable person would do given the same circumstances.
As someone interested in biblical backgrounds, I found particularly fascinating Graves’s well-researched details about Claudius’s friendship with Herod Agrippa (who killed James and arrested Peter) and the two rulers’ views on the early Christian movement.
In I, Claudius (a funner read) the reader wonders, “How in the world is this person considered an idiot going to (a) survive and (b) convince anyone of his worthiness to take the throne? The question for the second book is this: “When and how will his wife kill him?” In case there's any doubt, as was true of so many in the Julian line, the favorite modus operandi was--what else?--poison.