Answer: POWER WAS EVERYTHING, AND STILL IS.
Explanation: In an age where pride, land and family were everything, you could only open your way as a remarkable individual or as a group of people by leaving a path of blood.
Belical encounters were not so usual as you may thing. Believe it or not issues between families or dynasties used to solved with a diplomatic decission.....or with face off between the most powerful warriors of those families.