There's a term, coined by Jo Walton, for the problem writers of historical fiction face when confronting their readers' expectations of history. It's the Tiffany Problem.

Tiffany was a real medieval name, not even a particularly uncommon medieval name. It was traditionally given to girls born on Epiphany. (My birthday, as it happens.) But using it in medieval fiction would absolutely pull a modern reader out.

Readers of historical fiction might not blink at potatoes in medieval Europe (even though it's a Peruvian crop that wasn't available to medieval Europeans) but they would flinch at Tiffany unless they were, like, medievalists or people who have a lot of trivia stored up.

History is big and differs wildly depending on location as well as time, so even historians and history nerds have some Dunning-Kruger aspects to our historical expectations.

Most of us have very general knowledge of social mores and tend to assume they'd always apply. Like, I saw someone complaining about the portrayal of a couple living in sin in the fifties because in "real life" their community would shun them.

There are plenty of examples of couples living together unmarried and unshunned at every historical juncture. The fact that it was widely frowned upon doesn't mean that every unmarried couple would be routinely snubbed by their community.

An example I've complained about before is assumptions people have about historical marriage, assuming large age gaps as routine, marriage at a shockingly young age, routine arranged marriage, etc.

Historical marriage did not look like modern marriage, but not for those reasons!

When people complain about something being historically inaccurate, it's usually for bigoted reasons: women with agency and/or people of color in spaces white people like to think were historically white, especially if the people of color have agency.

Or it is because we know a little about history and make bad assumptions that universalize the little we know.

An important point regarding my use of "Peruvian" upthread. Native knowledge precedes the colonial nation. https://twitter.com/NonBidenHelper/status/1296911213918597121?s=20