THE DECIPHERED LETTER OF JOHN II OF ARAGON: A SECRET PLAN TO CAPTURE GENOA
The article presents the decipherment and translation of a little-known letter (1460) of King John II of Aragon found in the archive of the Saint Petersburg Institute of History of Russian Academy of Sciences. The author demonstrates his own approach to the decoding of the homophonic substitution cipher, which was popular in the Middle Ages. The resulting Latin text reveals the secret plan to capture Genoa proposed to the Aragonese King by Francesco Sforza, Duke of Milan. The Republic of Genoa in 1460 was under control of John II, Duke of Lorraine, who launched war a year earlier against Neapolitan King Ferdinand (Ferrante) I, nephew of John II of Aragon.