Hi,
I did a bit of research after reading your exerts and found some other book covers that has somewhat similar vibe to the one I'd like to see in yours. Among them, I love the covers of Katherine (Anya Seton), The Scarlet Lion (Elizabeth Chadwick), Mistress of the Art of Death (Ariana Franklin), The Slum Angel (AnneMarie Brear), and Exiled Duke: An Exile Novel (K.J. Jackson).
One approach I'd like to try is the style of romantic era paintings. Although the story is based on medieval era, I think the dark undertone of romantic era paintings goes best with this story.
Another approach would be an image montage using stock photos. The final cover would look somewhat like a scene from a period movie, or maybe a little abstract.
I usually love to do covers in minimalist vectors images, but I feel that style won't go very will with this genre. However, if you'd like to try that style, please let me know.
I'll give you the first version(s) of the cover within 7 days (usually sooner than that; like in 3-4 days). I might come up with more than one option with different look n feel, and you can choose which one you want to proceed with.
If stock images to be purchase, you'll have to buy those license separately. If you have budget restrictions or don't want to spend any extra on stock images, please let me know, so I can look for free options.
Looking forward to work with you.
Cheers!