What is the relationship between human rights law and the law of armed conflict? This is the research question at the center of the study presented in this treatise. After setting the stage of the inquiry in the introduction and prolegomena, Book 1 explores historical developments related to three turning points in the history of political thought: the close of the Roman Republic, the development of the first extant legal codes in early medieval Britain, and publication of the works of Hugo Grotius in the early modern period. Book 2 then examines the central research question from conceptual and practical perspectives. The study concludes that there is no relationship between human rights law and the law of armed conflict. Rather than a close relationship or merger, the study identifies a number of connections between the two bodies of law. In contesting the prevailing perspective that human rights and armed conflict share some manner of close bond, the study presented in this treatise seeks to recover the conceptual and practical space between peace and war while preserving the enduring legitimacy and effectiveness of the law of armed conflict.