It was interesting, because I'd never thought to refer to Nerath (aka The World, "Points of Light," or Nentir Vale) using this term. I took a look at Heroes of the Fallen Lands, and it does appear in the lore section at the beginning of the Fighter class. Here's the text (emphasis mine).
It isn't capitalized, so I took it as a reference to the empire of Nerath. However, it has a nice ring to it. I'm not sure it applies to the whole setting, but it ties in to a "Points of Light" setting reflecting that the land has now fallen.Heroes of the Fallen Lands wrote: This style builds atop the foundation of whatever early training the fighter received, whether formal schooling in the military arts or trial by fire on the borders of the fallen lands, and then borrows from the styles of every opponent the fighter meets.
On an aside, Heroes of the Forgotten Kingdoms refers to the "forgotten kingdoms" twice in the introduction to the Cavalier sub-class (emphasis mine).
It's less clear to me what "kingdoms" are being referred to here. Bael Turath seems unlikely. Maybe Arkhosia? Is this another reference to the empire of Nerath?Heroes of the Forgotten Kingdoms wrote: At one time, cavaliers formed into chivalrous orders that were dedicated to the ideal of protecting the civilized realms. The forgotten kingdoms that ruled the land relied on cavaliers to help keep the peace. Those cavaliers maintained not only the military security of the land, but also its moral strength. A cavalier might drive off a marauding troll, but she could also mediate a dispute between two farmers, break the power of a corrupt noble, or free a wrongly accused prisoner.
As with many things from the time of the forgotten kingdoms, the cavaliers’ glory proved fleeting. The kingdoms of old grew weak, and some of their decline could be laid at the feet of cavaliers who strayed from the righteous path. All too often, cavaliers fell victim to the very evils they had sworn to combat. Power corrupts, and in many cases cavaliers served as perfect examples of how power can twist the most resolute heart.
Returning to my original point, what do you think of using "The Fallen Lands" as a title for the Nentir Vale's setting?