Karmite

Wars of the Odokari
The Kidarites may have never had the chance to recuperate from their defeat, if not for the series of wars that followed Atechandar Argead's death in 838 DA. His generals tore the empire to pieces while the Kidarites recovered and regrouped. Isolated in their kingdoms in western Anidara, the Kidarites weathered the chaos of the following centuries. After unifying them once again, Kosran's first act as Shahanshar was the conquest of the Kotomeic Kingdom, the last of the Argead Successor Kingdoms in 1350.
A Vitrian minority ruled over a Vardanian majority through military might. Vardania had been bled white by the War of the Seven Princes, Reign of Seron the Red and Vitrian Uprisings. As a result the population numbers in the western regions of the continent dropped by as much as 50%. The near constant warfare of the era caused further devastation and detoriation of the land while the east recovered. In the end a combination of Vardanian rebellions and invasions from the east destroyed the weakened remnants, the last Vitrian Realm falling to a Feran Attack in 2634 DA.
Civil War caused by a succession crisis. An unclear succession leads to chaos after the death of Emperor Eugeron Valerius in late 2209 DA. Over 22 relatives with strong claims to the throne existed. Over the cause of 14 years, the Valerian Dynastie would destroy itself, only Seron remaining at the end. Finally with his death in 2242 DA the line went extinct. The war devastated Vardania and destroyed the 2nd Hegemony. Outlying territories had been either declaring independence or been taken over by foreign powers.
While Seron "The Red" managed to restore order in 2224, his reign was unmatched in brutality, military might the only way he could keep the ancient, decaying corpse of a nation together. Additionally, the Vitrians, a western people that had migrated into western Vardania in the preceding two centuries, had begun to become unruly during the War and now began to openly revolt. Following Seron's death in 2242 DA, the Vitrian Uprisings dealt the death blow. The 2nd Hegemony ceased to exist and most of the continent would be under foreign rule for the next 3 centuries.