Vale of Wolves
The Chaos Plague refers both to the original outbreak of uncontrolled magic, to the lingering effects, and to the occaisional upswells of foul energy that still sweep through the World today.
Some eleven hundred years ago, the world lived in a kind of order; High Gods with strange names like Aldaboath, Isdir and Sheor protected various civilisations from natural disaster and the predations of Monsters, and the Low Gods were at their weakest, held back by the weight of faith. An internal struggle amongst the Eternals distracted them from their watch, however, fracturing their power bases, ruining the World of Composition and allowing the Low Gods a means back into the Worlds. Slowly, at first, the power of the Occult Traditions increased, but with each victory by a Wizard-Lord and each city that fell to the hordes, the walls between The Worlds grew thinner and Chaos began to run rampant. New races, previously unseen in the World, began to march to war, although not all on the side of the Demon Lords (the nomadic warbands of the Gen being a notable example). Spontaneous magic began to twist the fabric of the world, with great geomantic arrangements growing in forests and mountains and squalls of power bringing turmoil to air and sea. The power of the High Gods seemed insufficient to stem the momentum of the plague, and were it not for the intervention of The Prophet, many believe that Creation would have crumbled once more into the Maelstrom.
The deeds of The Prophet and his revelation of Refinement are well known, but although he turned the tide of the Chaos Plague, he did not stop it outright. The effects can still be felt today, in the form of wild magic, raids from the Unrefined Races, and the responses of the Chancery.