Frili:
Anachronist:
I could see it going to very interesting places if you were to find a dedicated and historically literate group!
I plan on doing the heavy lifting there if needed, although I'm not entirely knowledgable in my own history (I'm from Belgium, my last name is Bourguignon, which mean "of Burgundy"). It's mainly a jumping off point for an alternate history moment, where magic is real and things might change. Like, the Count of Nevers and Rethel normally dies not many years after, still hiding in France, but should the players decide to try and hunt him down, these things might change from history.
I mainly like using a historic setting to have a more definite flavor and avoid a more vanilla fantasy vibe. And it gives me a lot of things to draw upon. I don't have to come up with NPC's that much, even though I invented the Castellan of this intro blurb. There's a lot of room for a "what if" type of mentality.
The only thing I'd say (and I'm aware I'm dipping my oar in far deeper than is probabl polite) is that historical settings are good for flavour but you may have to be quick on your feet as to explain why that's the point to diverge from the official timeline, and why this stuff hasn't happened (or been known to happen) before.
I've run a couple of games using a semi-historical timeline and there's a bit of a risk about how much you tie your hands using existing historical facts rather than fudging the specifics and capturing the feel of the piece, and it can really end up frying your canon.
It's not impossible, by any means, and if you can do it well then it's a really good experience. Just beware because you'll get some players who don't want or have the time to do the research and resent the players who do, and others who will and then demand how X is canon given the chronicle from the period specifically cites Y, and use it as an excuse to try and take liberties or metagame.
If you take this forward, it might be worth picking a point about 50 years previously and then build a kind of 'pocket universe canon' into that period which is where it diverges from the historical - it means you can create a canon which everyone can access but which preserves the verisimilitude of the setting. That, or run a kind of Assassin's Creed/NWod 'hidden history' which never makes it into the official records and which has some precedent.