I'd say that it'd be more primitive than the modern era, but not prehistoric. Without too many technological advances. It's difficult to come up with a named era for that, I'm trying to think.
And generally, the world would be sectioned off with one half being for the dragons, and the other being for the humans. That's pretty much how it worked from the beginning, but since the war had broken out, humans had invaded their territory and pretty much offed many of the dragons that thrived there.
So there'll be some places that are left pure and untouched by humans, probably further from the boundary between the dragon and human territory, while the land nearer to it would be more and more pillaged and rugged.
Does that make any sense, or am I just rambling here?