This situation began to change in the 12th century. One reason was that the State had become stronger. But there also had been an ideological change. The State no longer saw itself as an honest broker for violent disputes that did not challenge its existence. Jurists were now arguing that the king must punish the wicked to ensure that the good may live in peace. The Church itself was coming around to this view through what may be called a medieval synthesis of Christian morality:
A quick and fascinating summary.