Dwarf

Origin and evolution
The dwarves derive from the earthen, a prototype race of humanoid creatures consisting of living stone. The earthen were one of the races created by the titans in order to help shape Azeroth after the titans were gone, a so-called "Subterranean being matrix". As creations by the Vanir-titans (probably Khaz'goroth), the part of Azeroth the earthen were to shape was the earth and underground. Although the earthen was a successful creation at first, things would soon change. The Curse of Flesh created by the Old Gods affected the earthen, causing them to mutate into the vicious troggs. As the troggs had a very reduced cognitive ability compared to the original earthen (and other unfortunate aspects the titan's didn't find pleasing, such as cannibalism) the troggs were sealed away, primarily within the ancient Titan city of Uldaman.

Although the earthen were susceptible to the Curse of Flesh, the Titans chose to modify the prototype rather than begin all over again. This modification created earthen referred to as "Series Two". These earthen did not transform into troggs, but into dwarves. While the transformation turned their physical bodies mirroring the stone found on Azeroth into weaker flesh, they still maintained their mental affinity for it, along with their cognitive abilities. The dwarves were actually akin to a return to the default subterranean being that the Titans typically created. This had not been the titan's intentions and they would continue to modify the earthen, but they were satisfied with this outcome, seeing the dwarves acceptable to carry out their task in their own right.

When the Well of Eternity imploded at the end of the War of the Ancients 30,000 years ago, causing the Sundering, the transforming Series Two-earthen were deeply affected, feeling the pain of the earth as if it were their own. They retreated to the places of their origin — the Titan cities of Uldum, Uldaman, and Ulduar — and hibernated for almost eight thousand years. When they awoke, many of them found that their powers over stone and earth had waned and that their rocky hide had softened to smooth skin. Emerging from their Titan-homes, the dwarves from Uldaman made their way out of the Titan city and eventually built Ironforge in Dun Morogh.

This transformation along with other factors have created several different kinds of dwarves. Sometimes the differences derive from different ways of living and philosophy, but often they manifest themselves in the amount of change a dwarf has evolved from the earthen. Some dwarves, like the ones living in Ironforge, has undergone a rather complete transformation (with the exception of Stoneform, see The Explorer's League below), becoming fully fleshy creatures. Others seems to have undergone a semi-change, having aspects of both a fleshy creature and the traits of the earthen, like the Frostborn. The Titans eventually found a way to make earthen that were immune to the Curse of Flesh, which became newly produced by the Forge of Wills and other systems. These earthen never experienced being affected by the Curse of Flesh, still consisting of soil and stone, such as the few remaining Eastern Kingdoms earthen found in Uldaman and the earthen of Ulduar found in Northrend.

Although the titans marked their presence all over Azeroth, dwarves evolving from earthen are limited to Northrend and the Eastern Kingdoms. In Northrend, the original earthen from Ulduar evolved into the Frostborn while in the Eastern Kingdoms, the original earthen from Uldaman evolved into Ironforge dwarves (which later split into the Wildhammer-, Dark Iron- and Bronzebeard-clans, see War of the Three Hammers below).

Dwarven clans
Bronzebeard clan

Stonefist clan

Wildhammer clan

Stormpike clan

Dark Iron clan

Subraces
Frostborn

Iron Dwarf

Troggs

Earthen

Dwarves that arrived through the Portals
Shortly after Vamir destroyed everything, two portals opened up into different areas and Civilization started being built around them.

Xen'Drik's Dwarves

Faerun's Dwarves