Way back in the day it was supposed to be: The sovereign was special, he had essence. He was also a badass because of the essence. He could use that essence to a) remain a badass improve his kingdom with his essence, becoming weaker and the kingdom becoming stronger and c) imbuing essence into champions for spellcasters, becoming weaker but increasing flexibility. Essence was a finite resource, and the only way to increase the total essence pool was to have offspring. Offspring would then be a non-imbued magic user if the parents had magic, could be used as champions/generals and/or bartering/diplomacy.
At least that's what I wanted it to be, I can't remember if it was actually supposed to be that way
I also wanted it to be that the game kept a real score, and then you could play with a "family" of a nation, nation 123. I start my first game with Sov A "Dad", he's on a blasted world and has to start taking it over - using his very own essence to create life, becoming weaker as more fertile areas are created. Over the course of time he gets old. before that, he has a kid with a random champion he picks up - Sov b, who at this point is just a hefty champion. If Sov A uses all his essence he can die, so he might just die off - making Sov b, Sov B the new ruler. Sov B wins the game, yay.
The next time you crank up the game you'll see that nation 123 was started by Sov A, now deceased, and Sov B is available to play with - retaining some of the benefits of age/experience/loot from the prior game. If there were multiple children, they're available as well.
blah, blah, blah with the idea that you could have an empire/family etc that grows/evolves and it can track prior history.