The King did the correct decision. That's how Royalty works. He was destined to be an enemy so cut it down.
This was surprisingly a funny and heartwarming chapter. With such serious characters, it can't help but make you chuckle amusingly.
This world is way too primitive, even worst then Middle Ages. And the Politics is like Child-play compare to what I've seen in other Mangas/Novels. But it's understandable this way too.