Asgali Empire

The Asgali Empire, often called simply “The Old Empire” in the lands it formerly encompassed, was an imperial state centered in eastern Rhydain which arose circa 100 CV in the aftermath of the Great Cataclysm. It lasted roughly seven and a half centuries (in various forms) before its final collapse in 844 CV. The Asgali Empire is also sometimes referred to as Asgalia, although this is uncommon. Alternately, "Asgalia" today may mean just the area of the lower Taefemach centered on Modrinia, since this was the heartland of the empire and the site of its capital, Thandrium (which stood very close to the present-day location of Hakoris). 
The Asgali Empire was one of several successor states which grew strong in the post-Cataclysm period, filling the power vacuum that Qoss’s destruction left all around the Sarpic Seas. Other such successors included the Phyridian Empire (the Asgali Empire's major foe for much of their history) and the major pre-Kirdan Uremite kingdoms. The increasing size and strength of the Asgali state eventually put a stop to Uremite migration into Rhydain, which had proceeded on a large scale in the two centuries after the Cataclysm. The fledgling Asgali Empire was also able to wipe out the marauding orcish tribes that had menaced the Taefemach since the Cataclysm, when the collapse of Qossite authority allowed orcs driven from the Adhemars by Kuzul-Kadrin's expansion to descend on the lowlands. With the orcs exterminated and the Uremite migrations stemmed, the young Asgali state was able to consolidate its power and then enter a period of rapid expansion. 
At its height around 400-500 CV, the Old Empire controlled most of non-dwarven Rhydain east of the Redcrags, as well as eastern Taijuria, much of the Sornele, and substantial holdings north of the Sarpic Seas in areas like Phoacia, Ekhroa, and Istrium. Over the centuries, it was often in conflict with the Phyridian Empire, and to a lesser degree, with various Uremite kingdoms. These wars eventually weakened it and led to its downfall. The collapse of the Old Empire led to the emergence of a number of smaller states in its former territory, such as the Helvandrian League, Gundarra, the Free Duchies of Tythium, and various Alondrian principalities; it also allowed a then-vigorous Phyridian rule to be firmly extended over many formerly Asgalian or contested regions, although now, centuries later, Amran’s own control is also much weaker in those areas.
The collapse of the Old Empire was a case of slow decline, followed by a series of military disasters at the hands of the Phyridians and allied Uremites, leading to internecine civil conflict and ultimately the destruction of Thandrium and several other major cities by the armies of rival factions in these civil wars. In the chaos, most of the empire's far-flung provinces ended up on their own: Either taking advantage of the situation to break away under ambitious governors who wanted to make themselves kings, or forced into self-governance under local elites due to the end of imperial authority. Plague and crop failures also struck at the worst possible moments. The resulting population collapse, combined with the destruction of the capital and other administrative centers, prevented any side in the civil wars from restoring central control or reclaiming the breakaway provinces. Chroniclers and historians still debate to what degree this escalating set of disasters was engineered (or at least helped along) by the machinations of the Phyridian war-mages.