Homicide can seem timeless, somehow, determined by unchanging human failings. But a moment’s reflection shows this is not true: homicide has a history. In early modern England, that history saw two especially notable developments: one, the emergence in the sixteenth century of a formal distinction between murder and manslaughter, made meaningful through a lighter punishment than death for the latter in most cases, and two, a significant reduction in the rates of homicides individuals perpetrated on each other. This book explores connections between these two changes. It demonstrates the value in distinguishing between murder and manslaughter, or at least in seeing how that distinction came to matter in a period which also witnessed dramatic drops in the occurrence of homicidal violence. Focused on the ‘politics of murder’, the book examines how homicide became more effectively criminalized from c. 1480 to 1680, with chapters devoted to coroners’ inquests, appeals and private compensation, duels and private vengeance, and print and public punishment. The English had begun moving away from treating homicide as an offence subject to private settlements or vengeance long before other Europeans, at least from the twelfth century. What happened in the early modern period was, in some ways, a continuation of processes long underway, but intensified and refocused by developments from the late fifteenth to late seventeenth centuries. Exploring the links between law, crime, and politics, bringing together both the legal and social histories of the subject of homicide, the book argues that homicide became more fully ‘public’ in these years, with killings seen to violate a ‘king’s peace’ that people increasingly conflated with or subordinated to the ‘public peace’ or ‘public justice’.