Who built Nox Aeterna? This is a question I have asked myself many times. The Grim North is based on my own homeland in the North East of England with a thousand fantasy influences from Norse and Celtic mythology, Howard, Lovecraft, Gemmell, George RR Martin, Joe Abercrombie, and everyone else who wrote a cold, bleak Northern setting where life was tough and the inhabitants were too. So where does this dark, many spired metropolis of strange cults and high intrigue fit into the landscape of dark faerie beasts and warring barbarians? It's hardly a medieval analogue of Middlesbrough or Newcastle. Although each represents about the same chance of getting glassed in a tavern.
So the image of this hideously deranged mass of towers poking out of the snow covered moors, looking for all intents and purposes like it was the architectural brain child of Tim Burton and Euronymous while both were cracked off their tits on acid and pure evil, is one born out of Lankhmar, Gotham, Dark City, and Zak S's Vornheim. This place was built by a mysterious race of dread, godlike beings known to the state religion who worship them as the City Fathers, the Builders, the Hidden Masters, the Unbidden Creators or any of a hundred different names. They are cast as tall, emaciated and pale skinned, hairless and robed in black. Some say they are immortal and still live, hidden within the city itself. Others claim that they live on only through sinister necromantic rites and exist as liches or vampires. Of course openly touting such beliefs will likely see a man dragged off to the battle pits to have the heresy chewed out of him by a pack of wolves.
If the City Fathers do remain in some sort of immortal slumber or foul unlife, then it is beneath the sewers, beneath even the crypts and mausoleums of the Dead City, somewhere in the deep ruins that they rest, waiting, until the fulfilment of whatever forgotten prophesies will presage their return. After so many thousand years who can say what would happen if such ancient and terrible beings should they arise? Except, of course, that no good will come of it..