The author of the letter and the cipher is Giuliano Caprili, Ippolito I d'Este's agent and canon of Eger. The cipher was used by Caprili and Perotto Vesach, count (comes) of Zólyom (present day Zvolen, Slovacchia).
At that age, the tasks of the couriers were extremely dangerous and required a great deal of responsibility. Despite their preparedness and their intense military training, there was always the possibility of an attack by robbers or political enemies, so it was necessary to prepare for the danger that the confidential information might be compromised by unauthorized people. The most frequent measure of precaution was cryptography. As it is shown by the source in the photo, one letter was often signed by several different characters, and some words, mostly personal names and toponyms, were "masked" as letters; in this case, for example, the names of the pope (el papa) (1), the King of France (el Re de francia ) (2), the Duke of Milan (el Duca de milano) (3), the remarkable Italian cities (4), and words like pace (peace) (5) and treuga (truce) (6).
The original record held by: State Archives of Modena
Reference code: Archivio di Stato di Modena, Archivio Segreto Estense, Cancelleria, Carteggio Ambasciatori, Ungheria, busta 4, Giuliano Caprile, 20 aprile 1519
Date of creation: 20 April 1519