Useful Exercise?

[Mark Knowles]

This cipher is of interest to me as it is from 1440, if it has been dated correctly, and there are not so many surviving early 15th century ciphers. It should also be Milanese as it was found in a box of Milanese Visconti correspondence. I only know of a few examples of early 15th century Milanese ciphers. The most significant being the Milanese intercepted enciphered letters in the Florence State Archives from 1424 which I have written about and done a presentation on. This 1424 cipher shows features that I have not seen in later ciphers and a huge jump in complexity from the Milanese ciphers from around 1400. I have seen a number of Milanese enciphered letters from 1446 and 1447, however I am keen to get a better understanding of the evolution of Milanese ciphers. This 1440 enciphered letter plays a part in filling that gap. I am still very interested in finding an example of a Milanese enciphered letter from between 1425 and 1439.