don't remember the name

I don't recall if it was either a manga or manhwa, the main character was a knight who served the sovereign (they were either an Emperor or a King), he reveals to his either friend or brother, that he plans to retire to the countryside, I don't recall the reason for it, but fast forward later, that friend or brother is kneeling before the sovereign and his wife (who was that friend's former fiancée, and married the sovereign), on charges of treason, and is to be executed. I know it's a lot, but I am hoping someone remembers what the name of it is, I didn't bookmark it.