re: If you were a king in the Middle Ages, how would you consolidate power

I'd do whatever is in my power to make sure they are all taken care of. You do that, the more power you gain. In reality, you can't make everyone happy so I would have to prioritize based on where I have to gain the most power. I'd imagine the neighboring Kings are the ones I have to make sure are the happiest, I serve in their best interest they would have incentives to keep me around. I'd somehow work something out where the Kings would contribute a small amount to one of the other groups so that I could stretch out my resources.

I'd have eyes and ears all over the place so I could gauge how things are going on everywhere. It really would depend on each specific situation, but I would stick with the basic rule of "don't bite the hand that feeds you" so whoever feeds me the most will get fed by me the most. Whatever groups would rather have me out, I would throw them a bone every once in awhile, just to give them less incentive to do anything extreme.