Depending on our tastes and definitions, we can take quite divergent views on what constitutes the beginnings of peace research. The range of possible dates becomes narrower when we think of the beginnings of peace research movement. I refer here to deliberate, organized efforts to mobilize the resources of different disciplines – especially, but not exclusively, the mathematical models and quantitative methods developed in the social sciences – for studying the conditions of peace and war. Even the beginnings of the peace research movement, however, cannot be dated precisely, since it is in the very nature of a movement that similar ideas and activities spring up almost simultaneously in different places and under different guises.