History as the Locals Know It
Nearly three decades ago, the forces of evil and darkness gathered north-east of Hommlet and constructed a huge temple. This was a bastion for their armies of gnolls, bugbears, ogres, trolls, and giants – not to mention the evil human masters of the place (and the demons and other foul creatures that served them).
From this awful place, the malevolent denizens unleashed earthquakes, storms, fires, and floods upon the countryside. Monsters were drawn to the area like steel to a lodestone. The Temple of Elemental Evil took three years to complete, but even in that short time, the forces of good knew that they could not abide such a place. The lands of Furyondy and Veluna rallied their forces and sacked the temple twenty-two years ago in a battle called Emridy Meadows (named for the site of the largest confrontation). Most of the evil forces were destroyed or driven off. The temple itself was greatly damaged, but the underground levels were extensive and dangerous even for those heroic folk. So the Temple of Elemental Evil was sealed with great magic, imprisoning a powerful demon within its confines.
Nine years later, bandits began troubling the area around Hommlet. Evil humanoids and strangely garbed priests were seen on the road. Within the following year, it became clear that the Temple of Elemental Evil was rising again…