I'm afraid this is going to sound like a terribly critical review. As you can see, I still gave The Historian four stars. I did enjoy reading it. I might read it again one day. I suppose I just expected a bit more, something like a deep literary novel with a paranormal touch. Having read it, I'm not sure if it's as deep or literary as all that, but that isn't necessarily the book's fault.
I really wanted it to say much more about the whole theme of history, but it seemed to have it's best ideas covered in the first chapter. It turns out to be one of several books I've read this year which consider evil as a theme. It did this in a very interesting way but it doesn't do your thinking for you. I suspect I ended up thinking things the author hadn't thought of. All that is fine. But if a book isn't going to do your thinking for you, the relevant details really need to be memorable so that you can think about them yourself as you go about life.
The Historian isn't really memorable. It doesn't have enough emotional impact. The relationships feel lukewarm and it wasn't scary at all, which is a bit disappointing in a vampire story. It's maybe over-aestheticized, not just in the way it treats people but in those postcard-like descriptions of Europe. It does make for a very nice little armchair tour of Europe. It does treat historical research as very much like a detective puzzle in which you have to track down clues - which is very accurate in my experience. It was kind of fun, in a longish way. If I read it again, it would be on an aeroplane or at the beach.