The Ghimlinor

The mysterious Ghimlinor Kingdom filled the bowels of the volcano, Mount Vylnilninyr, in the centuries before The Gloom.  When the mountain exploded at the beginning of the current age, the kingdom was destroyed.  Legend tells of the Lost Halls of Ghimlinor, remnants of the kingdom buried deep in the ground beneath Tidestone or Lake Nyrlin.  It is said that ghosts of the Mountain God, Nyrlin, inhabit these haunted halls searching in agony for their beloved dwarves who burned to death in the explosion, smoke, and lava.  But these are only bedtime stories.
The last living descendants of the Ghimlinor are the Granite Hill Dwarves who are descended from a few score Ghimlinor dwarves who were mining gems in the Granite Hills.  All other life was destroyed in the region.