The diplomatic correspondence between Heinrich Friedrich Diez, Prussian chargé d’affaires at the Sublime Porte in Constantinople, and Christian Konrad Wilhelm Dohm: its decipherment and historical relevance

Abstract Heinrich Friedrich Diez is recognized as the author of Denkwürdigkeiten von Asien (Memoirs of Asia) and served as one of Goethe’s advisors on oriental matters. In 1784 he was appointed as Prussian chargé d’affaires in Constantinople, where he attempted to negotiate an alliance treaty. During that time, he maintained a personal correspondence with Christian Konrad Wilhelm Dohm, known for his book Ueber die bürgerliche Verbesserung der Juden (2 vols., 1781–3). However, significant parts of this correspondence are written in ciphers, particularly passages in which Diez discusses political topics. This article presents, for the first time, the nomenclature and process of decryption and highlights the historical relevance of this correspondence.