Copy-pasted from the 9th Age Forum, in case anyone would find it useful in their own story-writing or suchlike:
You are free to use any and all of my stories and background material as basis for your background. You are also free to use any and all Warhammer illustrations of mine straight off, should you find anything useful. You’ll find the most dense pieces written by me and others in here, and the rest in the other links in my (Admiral’s) signature on CDO. And don’t miss Thommy H’s army book or Grimstonefire’s WIP Liber Chaotica: Hashut.
My tip is to make your own background as rich as possible, with as many possibilities for players to fit in their own strongholds and themed armies as you can cram into the fluff. There should be a bewildering plethora of different cults and sects worshipping different aspects of the same god, and even, heretically, different gods. There should be lots of nods to the wider otherworldly realm of Daemons, and lots of ties-in to your version of Chaos and Daemons. These are Daemonsmiths and enslavers of Daemons, and this should show in their mythology and permeate their worldview.
Likewise, their brutality and ravenous hunger for power, slaves and conquest shall be the lead words. Theirs is an imperial society built upon domination and the trampling of the weak; upon cruelty and fell deeds to make a heart of stone bleed. Their religious practices are ritualized cruelty, their language is harsh, their treatment of slaves and others is abominable. Their Dwarven roots are still apparent in their craftsmanship, their hardiness, their stubborn nature, their conservativeness, their loyalty to clan and kin, and their inventiveness; but theirs is a corrupted nature, a twisted nature, one defiled and violated by an unyielding and oppressive (bull) god demanding sacrifices, wars and great labours and monuments to be erected in His dark glory, to praise His might and virility, and to stamp His dominion and His chosen tribe’s dominion over lesser mortals and over life and nature itself. Theirs is a worldview of mysticism, of dark omens and of the capricious will of cruel gods on high. Theirs is a dark empire, a realm of shadow and flame, of ash and slag, of smoke and molten rock, of metal and soot, of enormous slave plantations and hellish manufactories and (primarily) open-pit mines scarring the face of the earth itself. They are a mysterious people, an enigmatic race, one obsessed with order and chaos alike. Their culture would be strictly patriarchical (in contrast to uncorrupted dwarves), with harems and polygamy where their distant, hated cousins are monogamous, and their entire lives would be geared toward producing as many children, slaves, crafts objects, great works, conquests and heinous new discoveries as possible. Theirs is a realm of wastelands, but not bereft of navigable rivers and coastlines. Always leave room for lots of naval combat, and the ability of powers to reach across the globe with fleets and battle all other factions!
Make abundant use of ancient historical sources in Mesopotamia in particular, but also in surrounding bronze age territories such as Anatolia where appropriate. Learn from Assyrian cruelty and propaganda, and from both Assyrian and Roman ingenuity, warcraft, industrious nature and brutal conquests. Learn from their systems of slavery, of their deportations and killings and maimings and flayings and geldings. Know that the Infernal Dwarves’ worldview is one of strength and weakness, of master and slave and of soaring ambitions carried on the broken backs of foes and slaves alike; not of right or wrong or good or evil. Their morality is entirely different. Ancient pagan/polytheistic religions will serve well as a basis here, not least in their mythology. Yet learn also from the 19th century industrial revolution, and make a twist for the darker, with uncounted masses of Orcs, Goblins, humans and others trapped in the treadmills of infernal industry. And by no means ignore Tolkien’s ingenious showcase of Mordor Orcs’ slavery in that nightmare landscape. And do not shy away from tying your version of Chaos Dwarfs well into the wider Chaos, as is right and proper.
Just a tip. Feel free to explore mine and others’ writings on CDO to see for yourself.