What did it mean when an teenth-century monarch intervened in a legal struggle between social unequals, and decided on behalf of the weaker party? How do historians interpret such an event? In the example under examination here—the cause célèbre of the millers Christian and Rosine Arnold in Brandenburg-Prussia (1770–1779)—the dominant opinion of two centuries has been that King Frederick II's intervention violated justice and the rule of law. Explaining this remarkable continuity of historical attention is easy, for the affair's effects on state-formation in Prussia were far–reaching. On the very day that Frederick ruled in the millers' favor, the king also sacked his chancellor (Grosskanzler), Carl Joseph von Fürst, as well as three members of Brandenburg's supreme tribunal, the Chamber Court (Kammergericht), all for ruling against the millers. In Fürst's place as chancellor, Frederick installed Johann Heinrich Casimir von Carmer, under whom began the process of legal reforms that resulted in the provisional Corpus Juris Fridericianum (1781) and ultimately the General Prussian Code (Allgemeines Preussisches Landrecht, or ALR) of 1794. To some extent, then, Frederick's intervention was the founding act of codification. But it is more difficult to explain the unanimity: with few exceptions, historians and biographers have pronounced the intervention a “judicial catastrophe” (Justizkatastrophe) and declared the millers mere “troublemakers.” This essay will argue that such conclusions are misguided: by framing their questions within the parameters of legal and administrative history, most historians have focused on the legal merits of the Arnolds' suit. In so doing, they have operated on the assumption that a unitary definition of justice prevailed in eighteenth-century Prussia; as a result, most historical appraisals reflect highly partisan contemporary interpretations of the case. But there were at least three distinct “discourses” on justice at work as the case unfolded, each of them corresponding to one of the principal sets of actors in the drama.