In the first book, the Empire Strikes, the Kaisar united the South and fought hard against the North, conquering the whole continent. He established a new rule and the world was at peace. But there was a catch. While the South continued to progress like a speeding bullet train, the North's progress came to a sudden halt and moved at a snail's pace. Sure, both sides were still relatively at peace but one side was clearly reaping all the benefits.
I got a clearer picture of the whole thing in 'The Divide Continues'.
In the distant past, the two sides were somewhat conjoined. The North was always a backwater place compared to the South. The people here were peasants and were ruled by some elites and self-proclaimed superiors. Also, religion seemed to be a dividing factor.
