The containment of violence was central to the mission of medieval Japan’s warrior governments, the Kamakura (1185-1333) and Muromachi (1336-1573) shogunates. It was also vital to the survival of the warlords who vied for supremacy in the war-torn sixteenth century. The two shogunates received their mandate to govern from the imperial court. They became, therefore, keepers of public order; the violence of political adversaries was by definition criminal and partisan; the force with which the shogunates responded was an act of peacemaking. With growing political turmoil in the fourteenth century, the shogunate attempted to finesse distinctions between intolerable aggressive warfare and acceptable defensive warfare. The second shogunate collapsed in the sixteenth century and the frequency and pitch of armed confrontations grew dramatically throughout the provinces. The most successful among the rising warlords began to claim the right to legislate on the sole strength of their success. Relying on noexternal source of legitimacy, their laws drew power from the much greater severity of their punishments and the much fuller delegitimisation of all violence other than their own, as seen in the abolition of all distinction between offensive and defensive violence.