Ancient History:
Chaos Dwarfs began as Chaos Renegades back in the early days of Warhammer 2nd edition, essentially as mutated dwarfs and short, stout Chaos Warriors. In 3rd edition they began to add artillery elements to the Chaos forces, in the form of mortar teams, sky rockets, and bazookas - see [[Early Chaos Dwarfs]] for more detail - but were still essentially just random dwarves fallen to Chaos. Among the strangest mutations (featured in early issues of White Dwarf) were the Boar Centaurs - dwarf mutants that had the upper torso of a dwarf and the lower torso of a great boar, and were used primarily to drive chariots and war machines. Hobgoblins too began to be defined around this time as a form of tall, Eastern-influenced Greenskin, as well as Black Orcs as a form of “superior” orc.
Chaos Dwarfs as we know them began properly in 4th edition, with a series of articles in White Dwarf by Rick Priestley that were later collected as White Dwarf Presents: Chaos Dwarfs (1994), and a series of models. Priestley completely re-imagined the Chaos Dwarfs, inventing their civilization, Hashut, and many of their rules from scratch. This is the traditional Chaos Dwarf army rules and range of models that formed the basis for all CD players for over a decade.
Instead of random mutations and one-off rules, Chaos Dwarfs partook of the slow movement, heavy armour, and high leadership of their Dwarf cousins. Unlike Dwarfs, they lacked rune magic and regular handguns, but had access to their own lore of Sorcery, cheap greenskin units (especially Hobgoblins and Black Orcs), blunderbusses, cavalry (in the form of Bull Centaurs, an evolution of the boar centaur concept), and powerful war machines (the Death Rocket and Earthshaker Cannon replacing the Sky Rocket and Mortar). The result was a relatively versatile and powerful army, and it was this version of the Chaos Dwarfs that inspired representation in spin-offs like Man O’ War and Blood Bowl.
Chaos Dwarfs were not updated for 5th edition, and in 6th edition were represented with a shortlist in Ravening Hordes (2002). Most of the Chaos Dwarf army from 4th edition was translated directly to 6th edition, albeit in a highly abbreviated format. Chaos Dwarf sorcery, for example, was no longer given a unique lore, but a selection of different lores was made available, and they were given a limited number of magic items to choose from - many of them relics from earlier editions that had not been Chaos Dwarf only, like the Obsidian Blade, but more or less thematically appropriate. The list also became dependent on the Orcs & Goblins army list to an extant, because it could still recruit Orcs, Goblins, and Black Orcs into its armies.
Sixth edition also saw the first new Chaos Dwarf model/unit in years, the Hellcannon, which was part of the [[Storm of Chaos]]. The new depiction of the Chaos Dwarfs by Gav Thorpe and others during that campaign and in the accompanying books and novels - particularly, Gav Thorpe’s [[Grudge Bearer]] - set the tone for both the official and unofficial lists that would follow.
Additions to the changing Chaos Dwarf concept during this time were many, slight, and pervasive. The industrial, sorcery-wielding Dwarfs were connected to ideas like daemon-binding, daemon-engines, blood sacrifice, and the creation of magic items in a much greater way than ever before. Their connections to other Warhammer armies, such as the Ogre Kingdoms and Warriors of Chaos, became much more concrete. Examples include the Ironback Boar in the 7th edition Orcs & Goblins armybook, and the Forge World model [[Ghark Ironskin]].
The 2009 [[Dwarfs of Chaos]] list, for example, was made for the Indy GT and featured many new rules for a Chaos Dwarf army, based on a combination of the 4th edition rules and the newer depictions of Chaos Dwarfs in Grudgebearer. The new [[Forge World]] models are based on the increased presence of Chaos Dwarf manufactured daemon-engines in various Warhammer armies - the [[Iron Daemon]] model, for example, is essentially based on the Ironback Boar and Iron Rhinox, and ultimately on the daemon-bound Hellcannon. The [[Infernal Guard]] is an entirely new unit, but with obvious base on a perversion of an element of Dwarf culture (i.e. the Cult of Slayers), continuing the theme from Rick Priestley’s original re-imagining of the Chaos Dwarf concept.