He's the sensible, would-like-to-hang-out-in-the-country-and-stay-away-from-all-this-mess sibling. But he can't, because a) he needs the palace doctors, b) he can't ignore his duty to the kingdom (to see someone sensible on the throne) and c) it's not like he can abandon Calpurnia to the wolves (although lbr, he needs her more than she needs him).