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

Well, that all depends on too many factors to list:
How educated are my peasants?
Do I have internal enemies?
What's my military's strength relative to my neighbors?
Do I have ocean access with a decent port?
What are my Naval resources?
What are my natural resources?
Has the Stirrup been invented yet?
Are my kids retards?
Do I have Muslim, Viking, or Mongol armies encroaching on my territory?
Are my borders naturally defensible?
Do I have onagers? Trebuchet's? Ballista?
Has gunpowder been invented yet?