Celestial / Cosmic
Around 2,850 BB, there was a pivotal year in duergar history. Led by the formidable Queen Duerra herself, the grim soldiers of her vast empire launched a series of offensives against their longstanding foes. Drow cities and illithid settlements bore the brunt of these attacks.
The exact nature of this conflict with the illithids remains a point of contention. Duergar narratives portray a glorious victory, with Duerra's forces overrunning a major illithid city and enslaving its mind flayer inhabitants. These tales claim that over the next century, Duerra and her surgeons delved into the captured illithid minds, unlocking the secrets of psionics – the "Invisible Art". They supposedly transferred this potent power to their own bloodline, forever altering the duergar race. Legends even go so far as to claim Duerra's psionic might was so immense that she reduced the entire illithid colony to her thralls. Illithid accounts paint a contrasting picture. They portray Duerra as a cunning leader who capitalized on a slave uprising, ultimately enslaving the illithids themselves. They claim the development of psionic abilities among the gray dwarves was entirely their own invention, a means to create a more efficient and controllable slave race.