There are ruins of an Old Empire laying around the world. None of our nations know where these ruins come from. Other than that, we have no commonality anymore. We don't speak the same language, we have no shared culture, and our technology is very primitive. The gist of the role play is that we are barely Neolithic cultures, or maybe Mesolithic cultures. We are struggling to rise our Kingdoms above the ash heap of nothing that came before. Some of us may have rediscovered how to make bronze weapons and armor, currency, agrarian life styles, and important practices of hygiene, etcetera, but none of us know the craft of steel.