The Miller Arnold case (German: Müller-Arnold-Fall) is a landmark 18th-century German court case and cause célèbre during the reign of Frederick II that raised issues relating to the concept of judicial independence. It is an example of the Kabinettsjustiz (transl. cabinet justice) of Frederick II, as he personally intervened in a case which had already been settled by the Prussian courts.[1]
The case is named after the miller Christian Arnold who together with his wife Rosine pursued justice for an alleged upstream diversion of the water supply to his mill by a nobleman that rendered the mill inoperable. They lost all court cases that considered the matter, but when the couple turned to Frederick II, the king inter alia quashed the decisions of the Prussian courts, imprisoned some of the deciding judges, dismissed Maximilian von Fürst und Kupferberg, a leading figure in the administration of justice, and restored the mill and its water supply to the Arnolds.