I'm not up on my nobility -- if he was Lord Dewhurst, does that mean he holds the title? In which case, he's not just some scion of a noble family, he's a duke or an earl or something. In which case, his younger brother, now the title holder, would have even more reason to want to avenge his death.

Oh, the tragic backstories that could come off of that one little detail. Because Tony is awfully young to be the head of his household.