The conspirators were hanged for 'high treason'.
He is guilty of 'treason'.
(..) and gave them to the Dragon Queen so she could bring her armies here to attack you. It's nothing compared to the treason you suffered at the hands of a family member, from what I hear. But still, it bothers me. Murdering them would make me feel a lot better. (..)2017 TvShow: Game of Thrones Title: Dragonstone Season: 7 Episode 1
(..) I'm not going to strip these families of their ancestral homes because of the crimes of a few reckless sons. So there's no punishment for treason and no reward for loyalty? The punishment for treason is death. Smalljon Umber died on the field of battle. (..)2017 TvShow: Game of Thrones Title: Dragonstone Season: 7 Episode 1