Ethnicity is one of the most salient and enduring topics of social science, not least with regard to its potential link to political conflict/violence. Despite, or perhaps because of, the concept’s significant use, all too seldom has the field paused to consider the state of our knowledge. For example, how do we define and conceive of ethnicity within the context of political conflict? What do we really know about the causal determinants of ethnic conflict? What has been the most useful development within this literature, and why? This volume comprises reflections from an international range of prominent political scientists all engaged in the study of ethnicity and conflict/violence. They attempt to synthesize what the field does and does not know with regard to ethnic conflict, as well as draw out the research directions for the immediate future in unique and interesting ways.This book was originally published as a special issue of the journal Ethnopolitics.