The Battle of the Hannian Plains (or Fields), took place in 1651 a.a.H between a coalition led by the Dumian General Gayo and the Weseringian king Kirod I of forces from the Northern Dumian Empire and allies against the Dark Legion of Demons and their vassals and allies, commanded by the Bazrrod demon general Bael, during the Dumian-Demon Wars. It was one of the last major military operations of the Northern Dumian Empire, although Weseringian and Hannian allied forces composed the majority of the coalition army.
The battle was strategically inconclusive: the Dumians stopped the Demonic invasion of Hannian. However, the Demons successfully looted and pillaged much of Hannian and crippled the military capacity of the Dumians.
When the Dark Legion returned 20 years later, in five years they will be able to destroy the Northern Dumian Empire with the Fall of Dume at the 1676 a.a.H: but as well a costly campaign for them, the demons will retreat to Polforia to lick their wounds.