In my ideal vampire nation, the humans aren’t an oppressed class as much as they are a protected one, because their blood tithes are needed to sustain the vampire population. Once upon a time there was a King who figured “Why not? Who’s going to stop me?” and decided to run a Meiyerditch to farm humans for their blood.
Humans started a series of ritual sacrifices to spill their own blood in protest to the slavery, and that King’s reign ended very shortly after when he was deposed by his advisors and nobility for his verifiably bad move. An eternal reminder that if their rights are ever infringed upon, they’ll starve the vampires to death. That King’s name was struck from history, known only as The Craven King for his acts.
To that end the humans aren’t allowed to serve on the frontlines to prevent spilling of their blood, but they are allowed to have certain officer roles away from the line. Those who show their merit are bestowed the gift of vampirism and adopted into a noble bloodline (or even start their own house as vassals to the one who sired them) because vampires being undead can’t reproduce biologically. Most houses are entirely made up of adopted scions loyal to their sire. Killing a human is one of the gravest crimes, for you are denying their rightful blood tithe in doing so.
It’s the paradise for necromancers, blood mages, and other practitioners of dark arts. Demands of labour are fulfilled via necromancy, freeing up its population to be free to enjoy the pursuit of dark magic in their eternal quest to impress a Vampire Lord to sire them. The Lords of [Vampire Nation] prop up cults of dark magic users across the [human empire] to wage a proxy war in exchange for promise of refuge in their land once they’ve fulfilled their purpose. To that end the border between the two empires is one of the most heavily watched part of the world, akin to the Korean border. Anyone caught trying to cross the border is automatically charged with treason by the Empire.
You know, your vampire nation reminds me a little of Heresh from Heroes of Might and Magic. It’s the necromancer land in the setting, and in the campaign from Tribes of the East, a Vampire Lord had a human noblewoman working for him who hoped to become a vampire herself through her servitude.
Ah, but that is the problem with writing fantasy-stuff… a lot of things have already been done before, and the art lies more in giving your own unique twist to it so that it still feels fresh.
Vlad von Carstein of Warhammer fame supposedly kept the human population at stable levels (although in peasant squalor, which to be fair isn’t different from many other elector counts) and had the added bonus of raising endless armies of undead to fight off foreign invaders. In Total Warhammer you can also levy human crossbowmen to fight alongside your undead troops if you control the proper region.
I think as far as examples go that one’s mostly a bit of a tongue in cheek wink at how awful nobility in the setting is, though - the vampiric bloodthirsty monster is nicer to the common people than the nobles were! For a more symbiotic relationship the dreaded Age of Sigmar™ has some good stuff where you have undead skeletons and such manning the walls and building houses for living people and doing other assorted tasks like that to make life for them a bit better, really like interactions like that honestly
Vlad was legitimately popular when he first ruled Sylvania before the beginning of the vampire wars.
Unlike his sadistic and tyrannical forebears, he mostly left his people alone. He was harsh but just, and when he single-handedly slew a bandit warband that was harassing his people, his popularity soared.
The peasants were willing to forgive weird sounds in the night and graveyards going empty.
He legit wasn’t that bad a guy, but he ruined his chance at popularity when he assaulted the Empire with an undead army.
Not in Sylvania, though. When he assaulted the Empire, the living levies of Sylvania marched with him. And the rest of the Empire was given the option of serving beneath him in life or slaving for him in death.
Ah, it’s a turn-based strategy game that I had a lot of fun with when I was younger. Part 5 is still my favourite of it. You should look it up on youtube sometime!