An encrypted letter by Charles V, Emperor of the Holy Roman Empire, has finally been decrypted after almost 500 years by a team around cryptographer Cecile Pierrot. The letter, sent in 1547 to his ambassador at the French court, revealed that the emperor lived in fear of an assassination attempt by an Italian mercenary. Loria describes the work as a collaboration of four researchers from Inria, Loria and the University of Picardie Jules-Verne, pairing computer scientists with historians. Klaus Schmeh identifies the cipher as a nomenclator with 120 symbols plus meaningless nulls, and calls the press “sensation” an exaggeration, since his blog readers have cracked many messages at least as difficult.
Under the reign of Charles V the Habsburg Empire included the Holy Roman Empire, the Spanish Empire, Austria and many more territories. Historically the House of Habsburg is quite interesting.