Clan Duergar

Clan Duergar was a shield dwarf clan of Shanatar whose members were eventually enslaved by the illithids and became the duergar, a race of gray dwarves.

History
The Clan was one of many who splintered off to form a new kingdom in the early days of Shanatar, venerating Laduguer in a strict theocracy, naming it Barakuir. The sub-kingdom held fierce rivalries with neighbouring Drakkalor and Ultoksamrin, which became conflict from about in the Spawn Wars.

Barakuir swore allegiance to Shanatar and the Wyrmskull Throne but Clan Duergar, the ruling clan of the sub-kingdom, became more and more tyrannical, leading more and more dwarves of other clans to flee.

During the Mindstalker Wars around, Barakuir became cut off from the rest of Shanatar, and fell to its illithid conquerers, who enslaved its populace for thousands of years. Eventually, as slaves, the inhabitants transformed into a new dwarven race known as the duergar (or gray dwarves). It rose up and liberated itself around, spreading out into the Underdark.