The Thayran Sage Chronicals
Reth Anon is a now deceased civilization. It was arguably the strongest Thayran kingdom in the years leading up to it’s sudden destruction following the Battle of Kull’s Scar.
Reth Anon was the last independent kingdom during the conquest of Ardurous Kull, and likely would have remained so had it not been destroyed. The kingdom stretched from the Barren Northlands, to the Dwarven mountain kingdoms in the west, and pushed up against (and in some cases into) the kingdoms of blah and bladeeblah in the South and East.
While the kingdom had a strong infrastructure consisting of road networks, local governments, healthy trade and border guards/keeps, it too heavily relied on the wealth and resources of it’s capital city Retano. The city had served as its centralized hub of commerce, knowledge, leadership, and wealth (There were no active mithril or platinum mines at the time which could compare to those which ran underneath Retano). When Retano was destroyed in the blast at Kull’s Scar, the rest of the kingdom was unable to survive as a self-sufficient kingdom.
Reth Anon’s lands and peoples were either absorbed in the coming years by neighboring kingdoms, dwindled to nothing but empty ghost town in others, and in some cases formed a new civilization out of the ashes of defeat (such as the blah marsh people).