RWBY: WORLD OF REMNANT
The western end of Sanus is a barren and desolate wasteland. Long ago, before man went and ruined everything, it was a paradise. In the center of the vast desert was an oasis unlike anything you've ever seen: A jungle bursting with natural resources, geographical defenses, and the world's largest recorded deposit of Dust. Nomads that survived the journey across the scorching sands settled down in this little hidden gem, and over time, the Kingdom of Vacuo thrived.
Unfortunately, comfort breeds weakness. While the rest of Remnant had to learn and adapt in order to survive, Vacuo's ancient society kicked back and lived a life of complacency. But when other, more developed Kingdoms set their eyes on everything Vacuo had to offer, its citizens couldn't do anything to stop them from taking it.
Years of human conflict, unrestricted mining, and ecological disasters have changed Vacuo. The paradise that was once there's now practically indistinguishable from the surrounding deserts. Citizens live in makeshift homes, uprooting and traveling frequently in response to the fleeting resources and occasional attacks from the creatures of Grimm.
After the Great War, a formal government was finally established, but by that point the folks living in Vacuo didn't care to uphold its laws, making Shade Academy the only real source of order in the Kingdom. But order isn't everything.
Vacuo may not be as prim and proper as the other three Kingdoms, but it's still standing. And the people there have a mutual respect for one another. See, there's only really one, unspoken rule in Vacuo: If you can survive here, then you're welcome here.
So, there you have it - Vale, Mistral, Atlas, and Vacuo. You know, Oz would always say that the four Kingdoms are a representation of what mankind is capable of when working together. Ha-ha, ever the optimist.
We sure could use him right now.