Varelay Upheaval

Karterus has seen the rise and fall of more empires than any other continent of the realm.  Ma'Ohari is the northern jungle region of this continent. 

The earliest and longest reigning empire of this region was a demon empire called Varelay.  This empire was formed by demons that eluded the angels that had beaten them during the Demon Spawn War.   In the Lith-Crillion Era, the Varelay came to dominate much of Ma'Ohari.  After subjugating most of the region, there emperor had problems keeping his demons busy, and when they weren't busy, they were fighting amongst themselves or jockeying for greater power, so they were put to work, along with their slaves, in massive civil projects.

One of the largest civil projects involved mining operations.  These were done so recklessly that they led to a long period of earthquakes and volcanic eruptions.  This period of volatility became known as the Varelay Upheaval.  The conditions wrought during this time were so bad that the kuo-toans of Tilnangau were forced into the Underdark.  The Varelay Upheaval, among other factors, would also lead to the downfall of  Varelay.