"It is the year 2000 of our lord Sigmar, and the Empire is in flames. The once-proud realm of the Emperors has fallen into anarchy and intermittent civil war. For the common folk of the Empire it seems that the end of the world is nigh. A thousand redemptionist cults have sprung up throughout the land. When the times are desperate, men turn to the last hope: the Cult of Sigmar has grown powerful as men flock to the temples and shrines in hopes of salvation. But as people flock the the shrines of Sigmar, the Dark Gods grow in power, too. More and more men turn to the warship of the ancient gods of Chaos, the eldrich deities who thirst for the end of the world. Truly it is a dark time."
"And indeed, exactly two millennia after the birth of Sigmar, a sign appeared in the night sky above Mordheim. A twin-tailed comet, the ancient symbol of the patron god of the Empire was seen amongst the multitude of stars. Ignoring the dire warnings of seers and oracles of the Shrine of Sigmar, the men of Mordheim gathered in the streets to rejoice the second coming of Sigmar, and the end of all strife in the Empire. Then after a week of joy and heady rejoicing, the meteor struck the city, sending up a huge column of flames several miles high. The sky burned red as blood, and a huge crater, one hundred yards across, appeared where a prosperous district of Mordheim had once been, forever blighting the capital of Ostermark.
"A perpetual darkness settled over the city. Few rays of light penetrated the thick black cloud swept up by the plummeting meteor and burning houses. The Sigmarite priests warned that many men and women were being possessed by the Daemons of the dark, and whispered that an evil entity had come to the city with the comet and now hungered for the blood of men. Soon the whole of Mordheim became a ruined city, populated only by the most desperate of the common folk.
"It was said that the meteorite that had struck Mordheim was no ordinary rock but a shard from the dark circle of Morrslieb, the black moon. Pieces of the meteor bought by alchemists and nobles. It was said that these Stones had power to heal the sick, turn base metals into gold and allow men to work miracles. The shards of the meteor became the most valuable gemstones in the Old World. The survivors told what had become of the beautiful city of Mordheim. The ruins were scenes of savage battles and gruesome sacrifices to dark gods. Now Mordheim is a city where death lurks behind every corner, danger fills all the shadowy alleys and ruined, labyrinthine streets. Death comes quickly here, in guises and forms too horrible to contemplate. Yet the promise of riches lures the avaricious as a candle lures moths, and thus more and more warriors come to the City of the Damned."
- Segments from City of the Damned article from White Dwarf #223