The Rookie Queen and Her Cheat-Code Ministers

You can tell from many details that this is adapted from the relatively obscure history of Italian unification. (Even those who like modern European history are probably more interested in German unification, which happened around the same time. Sheesh!)

Overall, though, it only borrows the setting. I don't recommend getting too invested in the historical parallels. Just read it as a light novel (which is what it is anyway).