In this case, I am starting with a massive idea and breaking it into chunks that might not be obvious from the outset. The main idea of this campaign setting is romanticism. The Peninsula of Plenty has many locations, cities, towns, kingdoms, and other places that will be described in detail by an in-universe author name Magarven the Mad.
Magarven, although crazed, has a pretty good handle on what is happening in his world. It is an era of peace and prosperity at the largest level, which does not preclude mysteries and conflict at a local level. For the most part, this campaign world has left the medieval age behind. He has stumbled on the idea of describing what is happening with imperfect information. Or more correctly, information he has not validated but wants to be true. He is operating from his ego over his guts. He wants fame for bringing knowledge to the masses. He doesn't see any possible harm because he believes this one volume of books accurately describes the world. It does but only poorly.
You might guess correctly that I am a history major. This process occurred in various parts of the world back in the 18th century and peaked in the mid-1800s. It spread from Europe to Russia and to both North and South America. This was not exactly a peaceful era, but romantics often portrayed it as such. This was really not a good time to take a romantic perspective or a good place to evoke powerful emotions. Emotion and feelings took precedence over logic and facts, which had a dreadful effect on historiography and the natural sciences of this era. People were basically making their own rules and creating their own version of history which was radically different from reality. As all of this was taking place, things were falling apart.
In writing as he does, Magarven is actually sending people with torches and weapons to marvel at the wonders of a world made of powder kegs.