This chapter examines international courts and arbitral tribunals as bureaucratic bodies controlling the social reality created by the definitional categories of international law. In performing their wide variety of functions, international courts and arbitral tribunals not only make use of the social reality created by international law but also exert control over it. This control over the social reality created by the definitional categories of international law is approached as a form of control over knowledge and, it is argued, constitutes a feature of bureaucratic processes. In contending that international courts and arbitral tribunals control knowledge in this way, the chapter projects an image of international dispute resolution processes as bureaucratic sites of the exercise of power. The chapter then identifies the type of knowledge that falls within the ambit of the control of international courts and arbitral tribunals, as well as the modes of control they use to control knowledge.