On the planes of what would in millenia to come would be called Quendor, a small ragged band of Human merchants ran for thier lives, accompanied by thier wives and children. The Hoard advanced behind them, arrows from thier poison bows slicing over head. The Human's ran as they only dreamed they could.
Ahead, in the distance, they could see a set of Dark Caves, desparte, and exhausted, they hid in the caves hoping to gain refuge from the Orcish brutes. Timidly, the band prepared themselves for battle as the Hoard approached. The leader of thier persuarers - a large battle scarred Orc with a red tunic, stood at the Entrance to the cave and halted. He spoke in a language the group could not understand -
"Let them hide in the Caves, what they find at nightfall will be more deadly then even thier likes bargained for", and with an Orcish grin, turned to walk away.
Believing themselves cornered in the dimly lite caves, the Merchants camped for the night and beleiving it to be a safe haven from the impending Orcish invasion settled down and began a rudimentary village.
Suddenly, one day, one of the children was missing. Thier was no sign of struggle, no trace of blood, no sound of feet against stone heard in the night. Nothing. The child was never seen again.
Time wore on, and as the makeshift colony grew larger, they delved deeper and deeper into the depths of the world - making use of Magical Tunnelling spells found amonst the wares of the colonial founders. Children and soon other's continued to disappear - always in the darkness. A spirit, who become a monster who became demon and then a legend was blamed. They named it the Grue, lurker in the Dark.
Still the population and power of the colony increased, and whereever they delved into the lifeless rock, the strange disasapearences followed. Colonies of other races took up refuge, and using thier skills they discovered something extradonary - Obisidena Blackrock. Magic Proof and nearly industructable, this became the building block of the Empire and the hallmark of it's power. Still, the disappearences continued.
For two thousand years the Empire grew, increasing in power every day. The educated dismissed the old wives tales of the Grues and began a search for other causes of the mysterious disappearences - but no one dared travel without a light.
Until the day the Empire was submerged in dark and it's great lights failed.
No one knows what happened that day, but it is believed that the Grues overthrew the Imperial cities in under four minutes. It is considered a matter of luck that some of the inhabitants were able to seal the Empire before the assailents were able to pass though the gates and ransack the world above. No one entered the empire. No one ever again left it. The legend of it's fall however lived on.....