Plains of Light (Stormforge Supplement)
From D&D Wiki
The Plains of Light is a both a terrible blight upon Aerinthia and a blessing to its people. The people of the plains have exhausted the resources of the dark armies of Shadar and while the city of Dros Corinth has stood as a bastion against the dark armies the oppressive theocracy that is the Citadel of Light also treats the people of the kingdoms as heretics. The denizens of the Plains of Light are plains nomads. The nomads often hunt down any that trespass on their lands and pour their blood upon the plains to fulfill a pact made long ago with their God-King, Kosun, The Enlightened One. However, if given proper respect the nomads are required by their customs to give hospitality to those who seek to fight the minions of Shadar. Warriors returning from battle against Shadar are expected to bring proof of their victory if they seek safe passage back across the plains. It is not uncommon for an adventurer who travels across the plains to meet more than one gathering of nomads since they keep no borders except the edges of the plains.