Recently converted Britons, if we're talking about the Middle ages and the wave of christenings that were occuring at the time, then we can say that they were at first somewhat reluctant about their new faith. Over time, however, they had grown accustomed to it and respected it deeply.
The principle that government can only do what its people give it the authority to do is called "popular sovereignty," since the people, usually through representatives, are in control of the direction of the state.
