Otherwise defined as USURPATION! Boo! Hsss! Hss! You set yourself up for a hard fall. I never minded you being the Duke of BR and what not, but now you will lose all of that. So sorry, I tried not to let you tie that noose! Swing!
You made a public announcement that you would have Sevastian's duchy stripped from him, and his lordship. Don't even play like you haven't been the aggressor in this.
You shafted yourself in this one mate.