The emergence of the history of international thought as a major subfield of International Relations (IR) is one of the most significant developments within the discipline in the past 20 years. Scholars working in the area have transformed our understanding of the origins and evolution of the discipline and the thinking about international relations that occurred prior to the coalescence of IR in the mid-twentieth century. Textbook caricatures of canonical thinkers and key texts have now been replaced with nuanced, historically sensitive interpretations of the work of major figures—from Raymond Aron and Hedley Bull to Hersch Lauterpacht and Alfred E. Zimmern (see, e.g., Davis 2009; Ayson 2012; Jeffery 2006; Markwell 1986). The evolution of important traditions of thought are now understood far better than they once were, as is their influence on various theorists and practitioners in far greater detail (see, inter alia, Ashworth 2014; Clark and Neumann 1996; Hall 2006a, 2012; 2014; Hall and Hill 2009; Haslam 2002; Holthaus 2014a, b; Keane 2002; Long and Wilson 1995; Navari 2013; Onuf 1998; Rosenboim 2014; Schmidt 1998; Rosenthal 1991; Williams 2007). As a result, we now have a much more robust and accurate account of the development of the discipline of IR and the wider development of non-disciplinary thinking about the subject.