Locarno Treaties
From 1914 to 1916, Frenken served as "Unterstaatssekretär" (under secretary) at the German Ministry for Alsace-Lorraine. In 1916 he became president of the "Oberlandesgericht" at Cologne. He retired as a judge in 1922, but in January 1925 became "Reichsjustizminister" (Minister of Justice) in the first cabinet of Hans Luther as he was close to (or actually a member of) the Catholic Centre Party. While in office, he was also in charge of the Ministry for the Occupied Territories. Frenken resigned on 21 November 1925, protesting the Locarno Treaties, which he had strictly opposed.