I think I still have a half written horror story based on 1971 Bangladesh Liberation War somewhere in the bottom rack of my shelf.
Apart from that some of my favourite themes are -
1) Futility of Partition of India - Two childhood friends / Battlefield buddies of Burma campaign/North Africa gets separated due to the partition. They meet again on a battlefield of 65/71 war where one unknowingly kills his once best buddie and only to discover that later. His repentance does not end even with his eventual death and in the form of a ghost he narrates this story to the narrator (1st person). Supposed to be a ghost story but not a horror one.
2) Mysterious disappearance of a French sub that escapes the German capture by escaping Toulon just before the destruction of the Frech fleet - could be an adventure or a horror (inspired by the real life story of FS Casabianca)
3) An Einsatzgruppen operation wipes out a village in Russia. Only one man survives and remembers the face of the major. He joins the local partisan unit and due to his bravery is noticed by the NKVD. Years later, as part of an NKVD rifle unit he finds his enemy by chance during the Battle of Seelow Heights (now somehow a panzergrenadier) and kills him brutally by his bare hands. Later in the ruins of Berlin he finds a lone baby with his dead mother and chooses to adopt it. Years pass, but the face of the major keeps giving him nightmares. Later to his greatest horror/dismay his adopted son increasingly looks like his long dead foe. He figures out the cruel joke of destiny to some extent by himself but chooses to suppress it, only to inform his son in his deathbed. The son's quest in search of his origins begins.
4) A horror novel set in the Ottoman Empire during the reign of Murad III. Theme - Janissaries vs undead Cataphracts (Cannot elaborate now as my Byzantine history is pathetic as of now.
That's it for now, I'll post if anything more comes to my mind.
Here's a strange one: A heartwarming tale of either a Chinese or Roman envoy visiting the other culture. We often focus on the decadence and brutality of Rome, but I'd love to see it through the eyes of a foreigner marveling at the government, the buildings, the religion. Really hammer home what a beautiful culture it was and the impressive feats they accomplished. And there could be lots of humorous misunderstandings between the two cultures as they try to explain the stranger aspects of their way of life.
Plus, we don't see enough about China, so it would be nice to explore that a little, too, on its own terms, rather than having poor Matt Damon running around the Great Wall
The coalescence of Europe, from about 900 a.D. to 1072 or so.
Featuring the influence of The Church (including the conflict of monastic v Rome) in its attempt to unify the continent(one king being easier to control than many) and the expansionary role of the Norse (from Norway and Denmark to Ireland to Scotland to Iceland to Greenland to Vinland to Constantinople, Normandy and Great Britain...)
Fascinating stuff; filled with violence, sex, adventure...
I have been having this idea brewing in my mind for a while actually, and I seriously think it could work - it is a perfect fit for the current era I would argue even. What is it then?
Simple: The lovestory between Martin Heidegger and Hannah Arendt.
I am honestly surprised it hasn't happened earlier. Heidegger could be played by Michael Fassbender, Arendt by... I don't know. Maybe his wife, Alicia Vikander? Or maybe someone who actually looks like Arendt (can't think of anyone right now though). The drama could also be able to put all of the political psychodrama of our times in the perspective of real philosophical differences (combined with a very gripping story, and fascinating characters) and if the directors actually have the cojones to not portray Heidegger as a comic-book Evil German Professor (hopefully) the movie could be really good. This movie might bring people together, and encourage empathy across the whole political spectrum. It would be glorious.
Or at the very least it could satisfy the latent forbidden desires of much of the Social Justice Warrior class, in a more intellectual incarnation of "50 Shades of Grey".
Regardless, I think it would be a fantastic film if done right, and I would love to watch it.