The Ash Valley, The Malathil, and Wingsong's defeat

Before I tell this tale, a word on 4th edition cosmology. The material plane consists of not one, but three worlds, parallel to each other. The "natural world" is the one that your characters spend most of their time in. A magical reflection of that world, known as the Feywild exists alongside it. Eladrin came to the natural world from the Feywild in very ancient times. The third world is the Shadowfell, a dark shadow of the natural world.

To the south-east of the Achauk capital lies a large area called the Ash Valley. Though this part of Terra Malatia is relatively flat, the Ash Valley is known for its hills and valleys. The high points are densely wooded. The low points often expose caves that descend into dark realms beneath the ground. The Ash Valley is a place where the natural world and the Feywild are quite close to each other. Fey creatures are common here.

The people of this valley are humans called the Malathil, a name given to them by the Eladrin. They are simple and primative people. Perhaps an effect of their Fey surroundings, some Malathil inherit animal-like characteristics. Individuals with these features often feel a calling to dedicate their lives to defending the valley. (In game terms, these special Malathil are the PHB2 race "Shifters'.)

A millennia ago, when Trakas Wingsong was at the height of his power, he had driven out or enslaved all of his neighbors. But he had left the Valley alone - fearing the magic that might defend it. Refugees from his defeated enemies had been given shelter by the Malathil. Some were attempting to lead a resistance. So Trakas decided to send his army into the Valley.
By some accident, some of Trakas's forces crossed into the Feywild. There they stumbled upon an Eladrin city. Not knowing what they had found, they looted this city, and burned it to the ground. This same band of marauders discovered a vast cave occupied by Drow. They massacred that as well.

In response to this attack, the Drow and Eladrin of Ash Valley struck a pact. The Malathil persuaded them to put aside their ancient differences and unite to push Trakas Wingsong and the Bahumati out of the Valley. They succeeded in doing this. This would be the greatest defeat of Wingsong’s life, signaling the beginning of his eventual downfall.

The fey alliance of Drow and Eladrin did not press their advantage to destroy Wingsong's empire. They stopped at the edge of the Valley. But they pledged to each other if Trakas Wingsong ever rose to threaten them again, they would unite to destroy him once and for all.
Soon after, the effects of the plague began to weaken the Empire. Trakas went willingly into un-death, in hopes to rise again at some future time. The Drow/Eladrin alliance is long forgotten by most.

Only the Malathil remember. And as the Auchauk kingdom begins to re-form, they wonder if it poses a threat to The Ash Valley. Perhaps they'll need to find a way to unite their neighbors against a common enemy once again.