Long ago, elves, dwarves and men stood side by side in a great alliance, fighting together against the first incursions to sweep down from the Jaws. The brotherhood of the three races was born out of necessity and, more so, an understanding that they were all the servants of the same god. The fighting was terrible, and many fell, but eventually the foe was beaten back to the Abyss. With the armies of men, elf and dwarf gathered in the mountains about the Abyss, a great spell was cast across the void, so that no demon or devil could cross from that land for a hundred years.
To ensure their safety, dwarves and men built great fortresses within the Jaws, while the elves cast wards and healed the scars left on the land by an age of war. Forests were re-sown and befouled waters ran clean once more.
In time, man forgot the devastation wrought by the Host of the Abyss and turned his attention to his cities and the conquest of unexplored lands, while the dwarves continued to work the stone of the mountains.
When the hundred years had passed, the elves returned, both to the dwarves and to the humans.
The dwarves showed the elves vast defenses, mazes of tunnels to confuse and bewilder their common enemy and traps to maim and capture the warriors of darkness. In their Holds, the dwarves had built great forges and worked the metals they had mined, turning out beautiful and deadly weapons, stored up in case war should ever return to the land.
Then the elves came to the kings of men, warning of the failing wards and reminding them of the old alliance. The kings, corrupted by their greed, blamed the elves for the failure of the wards and labeled them as collaborators, intent on destroying their kingdoms. They shamed the elven ambassadors and chased them from the kingdom.
The elves were left with little choice. Without their human allies, the elven wizards cast what wards they could, the Strands of Magic weakened by the absence of human mages. Then the elves left for their home in the Veiled Lands, to throwing up hasty defenses and prepare for the assault they knew would come.