This is a problematic book to review.
I gave it 3 stars, but that's a compromise between the inventiveness of the story (very high marks, somewhere between 4 and 5 stars) and character development/investment (1 or 2 stars, maybe). In a nutshell, I think what we have here is a book that puts too much emphasis on historical accuracy, and it does so at the expense of art.
Stuff happens in the book, no doubt about it. In fact, LOTS of stuff happens. However, for me it was about as engaging as following a bouncing ball: "this happened, then this happened, then this person said that, then that person said this, then something else happened, then..." Bump-de-bump-de-bump, on and on and on, and IMO none of it gave the characters any plasticity, nor did any of it engage me in the story. In fact, I found everyone in the book to be flat with the possible exception of the young emperor whose name escapes me, and he didn't pop into the story until late in the book. This is tolerable in a short 200 or so page book, but at 500+ pages, MC required quite a bit of effort to finish. That's a lot of pages to read when you really don't care about the characters. Like, any of them.
So, while I admire the level of effort that went into making this historically accurate, as a story it just didn't do it for me. I guess I prefer books that hold character development in higher regard than historical accuracy.
As always, this is just my personal opinion. Clearly I'm in the minority here, so caveat emptor.
I received this book as a Goodreads Giveaway in exchange for an honest review. I honestly think more time should have been spent with the Joffrey-like emperor. I didn't like the dude, but he added quite a bit of color. Just sayin'.