I, Claudius is a bit of a slog at times, since the central conceit - a man simply writing down everything that's happened to him, or rather one long list of people to whom stuff happened while he kept his head down and his ears open - is so well done that it really reads like that and often gets bogged down in detail about political assassinations rather than what's actually going on outside the palace walls. Graves later claimed he only wrote the Claudius books for money, and it does have a certain air of being written quickly, with more thought to authenticity than to literary greatness. Plus, it made me feel I had to rewatch Caligula and I'm not sure I can ever forgive it for that.

That said, you can hardly fault Graves for sticking (largely) to historical facts, and there's no doubt it's a fascinating and competently written story. It's just that personally I thought Derek Jacobi told it better than Graves. But still, as historical fiction goes, it's not the best I've ever read, but definitely above average - just not up there with the likes of Maalouf, Bengtsson, et al.