The Ending

200 years ago the Gods grew weary of the progress that the people of Nemed were making, and feared them becoming too powerful. They took it upon themselves to try and halt their progress, creating a rift in the veil between heaven and Nemed, using it to access the world. The most powerful spellcasters and armies of Nemed took up arms to try and stop the Gods from destroying the world. The ensuing conflict took many days, pummeling the land Nemed with the most powerful and destructive magic that had ever been seen. The immense power of the magic, and brutality of of the battle devastated the land, creating The Valley of Glass, and fracturing the continent. Most of the population and kingdoms were destroyed, but the gods were ultimately driven back. 
Forced back into heaven with their tails between their legs, the Gods repaired the tear in the veil to keep themselves safe from any retaliation from the people of Nemed, repairing a small rift that had been there for millennia. This caused magic to lose much of it's potency, causing casters to have to use alternate methods to use their magic.

The Conflict

Aftermath

The region of Nemed was forever fractured separating the nations and creating many fissures between land masses. Magic's potency was greatly inhibited by the complete severing of heaven from earth.

Conflict Type

Battle

Battlefield Type

Extraplanar

Conflict Result

The residents of Nemed emerged victorious but at a heavy cost. Magic was forever changed and the gods are largely absent.

Location

The Valley of Glass

Belligerents

Residents of Nemed

The Gods

Strength

Casualties

Most of the population, most notably the powerful spellcasters sent to fight.

No one knows the casualties the gods endured as they have been missing since.

Objectives

To defend their people and region.

To stop the residents from becoming too powerful, threatening their rule.