The southern most lands of the central continent of Nerath. Ages ago, Arkosh was the territory ruled by the Empire of Arkhosia, a powerful nation of dragonborn. However, after a brutal war with Bael Turath, which ended with Bael Turath making an infernal pact with the devils of the Nine Hells that resulted in the end of both kingdoms and the set forth the events that would ruin both Erthain and the Nerathi Empire.
After the fall of the Nerathi Empire, the southern lands of Arkosh, now cut off by the cursed lands of Erthain, sought aid from the newly formed Brelani Empire. However, attempting to forge a newer brighter kingdom for its own people, Onsingerion was unable to send aid and forsook the southern lands. From this insult, the people of Arkosh were devastated. Civil unrest broke out across the region and lawlessness and the rule of the blade became common place.
Realizing that death was all that awaited down this path, several dragonborn tribes began to rally around the thought of reforging Arkhosia anew. However, their prayers to Bahamut, patron god of the dragonborn, were mysteriously unanswered. In desperation they turned their desires to another god who would listen to their plight: Tiamat.
Tiamat gave them the strength to bring control back to Arkosh. She selected five of the strongest and most devout dragonborn and blessed them – one with each head. These five dragonborn became the first Clanlords of the Five Clans of Tiamat that have ruled Arkosh since.