So bizarre, somehow cut off my paragraph...
Anyway, I was going to say that provinces in war are generated free honor based on the duration of the war.
For example: Two KDs that have gotten to the free 1800 honor mark go to war against each other and make equal attacks (for the sake of my point, they Mutual Peace at the end of 7 days) All provinces from both KDs would likely at least be a Baron by the end of the war.
This MIGHT also scale with Free Credits & Books, that I HAVEN'T verified.
So think of the juicy rewards that you will get for staying the duration. :P