In 1965 ECKSTEIN opened up a number of analytical perspectives in a now classic article on cross-national analyses of political violence, the perspective in which we are primarily interested. Other pioneering works are the factor analyses of various forms of conflicts by RUMMEL (from 1963 to the present), the first broad comparative analysis of political violence published (FEIERABEND/FEIERABEND 1966), and GURR's study of civil strife (GURR 1968a), a first high point in theoretical and methodological sophistication. The end of the 1960s and first half of the 1970s have witnessed an enormous and continuing outpouring of studies on political violence, both comparative (cross-national) analyses and case studies. Most of these cross-national analyses study phenomena of political violence taking place after the Second World War. This focus is considerably broadened in the analyses of revolutions which are dealt with in later chapters of this study. Most of those analyses are comparative only in a very limited sense. Our aim is to evaluate these studies and to provide some guidelines as to the possibilities of cross-national analyses of revolutions. In the chapters on military coups d'etat, one of the dominant patterns of political violence in many parts of the world, and on crises and political violence, reference is again made to a number of studies generally covering periods after the Second World War, but occasionally, longer periods are treated, and in one instance a period of approximately one hundred fifty years is considered. As might be expected in cross-national analyses of this sort, variations in time and space are considerable, rendering the development of universally valid theoretical statements a herculean task. One purpose of the present study is to bring together various strands of research and to show or suggest where and how they might be fruitfully related to each other. In addition, our book is intended as a critique of existent research.