I think that the genre of historical fiction needs to have a new name. As an alternative, I propose “artefacts floating in front of a misty landscape.”
Consider if you will some recent(ish) novels by Tim Severin and Robert Low.
I wonder if it’s the same guys fighting at the bottom of the cover there.
I have always thought of this as being derived from the covers of Bernard Cornwell’s very successful Warlord books:
All three books show some kind of period(ish) artefact floating above a landscape or some fighting guys. And these are far from the only ones — there are dozens of books by these authors that follow this pattern, and you could probably point to loads more authors with the same design.
It’s even spread to older authors; a recent edition of Lord Geoffrey’s Fancy that I picked up a library booksale (I love me some Alfred Duggan) has the same deal, although he’s an earlier and very different writer:
And you even see it in fantasy fiction:
It’s probably not a coincidence that Martin is writing something not too unlike the genre of historical fiction represented by the novels above, sans the history and with a lot more dragons.
Sometimes I find myself buying novels in charity shops because they have a floating artefact on the cover. The problem is that if you do that sometimes you find yourself reading one of Severin’s books, an experience I don’t recommend.