While the focus of the book is on the interstate use of force post-WWII, this chapter holds a rear mirror and offers a perspective of evolution of restraints that started long before states came into being. It recounts how human societies over the centuries became states free from widespread internal use of armed force and how great powers sought to avoid major armed conflicts through policies of balance of power and multilateral conferences. It describes how they developed common rules by concluding conventions and built institutions such as the League of Nations and the United Nations to create a rule-based order and mechanisms and methods to prevent the interstate use of force.