Mercenary Empires (Endhaven Supplement)
From D&D Wiki
The Mercenary Empires existed between the Crusade of Light and the consolidation of the Thule Empire. They came into being when unpaid mercenaries seized the lands that they were supposed to be protecting.
Many such empires arose after the Crusade of Light. These empires fought for many years until they all fell under the sway of the Thule Empire. The history of these empires is poorly known and complex.