Regular Cipher Mysteries readers will know that I’m pretty good at digging historical things up, at shining lights under long-unmoved archival rocks. Well… my challenge this week was to find some mid-Quattrocento Milanese enciphered letters, and though I’ve possibly got most of the way to an answer, I’ve ended up a bit stuck, and would really appreciate some help from all you good people!

The starting point was that I was sure that the Archivio di Stato in Milan contains a vast number of documents from the period I’m most interested in (Milan’s Francesco Sforza era, i.e. 1450-1465), so that ought to be the first place to look for these. But (as is normally the case) relevant manuscript catalogues are few and far between online, so I initially drew a blank.

Then I (somewhat luckily) stumbled across a 1995 book online called “Fifteenth-century Dance and Music: Treatises and Music” by A. William Smith. Page 6 of its “Fifteenth-century Italian Dance Sources” chapter mentions a letter: “26 July Archivio di Stato milanese. Potenze estere. Napoli 1455. in cifre from Albrico Maletta, Sforza ambassador in Napoli to Duke Francesco Sforza in Milano.” Interestingly, f20v of the famous Tranchedino cipher ledger is marked as “Cum Francisco Maleta” (though this is sandwiched between a 1458 cipher and a 1459 cipher, so might well have been entered into the ledger later than 1455): all the same, it would be interesting to compare the two. But how to find the manuscript reference for this?

The first thing to note is that “Potenze Estere” is actually the name of a large set of documents within the Milanese Carteggio Sforzesco archive. Obviously, I then searched like crazy for (I’d guess a scan of a 19th century) inventory of this, but without any luck. So where next?

Then I remembered Aloysius Meister’s “Die Anfaege Der Modernen Diplomatischen Geheimschrift” (1902): p.30 contains a (surprisingly complex, I think) Milanese cipher key and nomenclator dated 14th March 1448, with the reference “Mailand, Staatsarchiv. Pot. Est. Cifre Fasc. 2 Nr 5.” There’s also a 1483 cipher (p.31) noted as “l. c. Fasc. 1 Nr 15” (interestingly, this contains a “4o” composite character (for ‘z’) but with the ‘o’ attached to the downstroke of the ‘4’), and a 1530 cipher key (p.32) listed as “l. c. Fasc. 4 Nr. 53 Grofs 4o”.

(I should add that Meister 1902 also lists ciphers for Modena, including one [p.35] dated 23rd June 1435 “In Milano” which fascinatingly contains “4” for ‘Q’ and “4o” for “Qua”. [“Canc. duc. Arch. Proprio Mappe II. Nr 1.”]: and for Florence, he lists the Cifra di Galiotto Fibindacci da Ricasoli 1424, which similarly uses “4o” for “Q” [p.50])

So there you have it: it seems that the Carteggio Sforzesco’s Potenze Estere archive contains several specific bundles of cipher documents (“Cifre Fasc[iculus/-i]”) that sounds like what I’m looking for. But then again, Meister was writing over a century ago and much may well have changed there: specifically, here’s a link to the best listing I could find for the pre-1535 part of the Potenze Estere archive, but note that there is no obvious cipher bundle or subset to be seen. And that would seem to be the end of the line – though I’d expect the 1455 letter from Naples listed by Smith is probably filed in the Napoli section of the Pot. Est. archive (which is more or less entirely arranged geographically).

At the end of all that, I don’t know whether I’m really close or really far away. Are the cipher bundles Meister referred to still in the Potenze Estere, and what do they contain? Or have they been moved, split, stolen or lost at some point during the last century? Regardless, where do I need to go to see them and what should I ask for? Any pointers you can turn up to help me answer these questions would be much appreciated! [Please leave comments on the page below, or email me at the normal address]. Thanks!

Update: I subsequently found a more detailed listing on p.927 of this sizeable inventory: it says that the Atti Ducali (1392-1535) section of the Archivio Sforzesco contains “Cancelleria segreta 1450-1535, scatole 11. Raccolta di documenti relativi all’attività quotidiana della cancelleria: sommari, cifrari, occorrenze (carta, inchiostro ecc.), archivio, documenti relativi alla biblioteca del castello di Pavia.” So perhaps the cipher documents Meister saw were later moved over to this Atti Ducali section?

Alternatively, the Carteggio Sforzesco’s Potenze Sovrane archive also holds a section marked “Cancelleria segreta – Chiavi e cifrari (scatt. 1591, 1597 – 1598)”, which is what Lidia Cerioni relied on for her book “La diplomazia sforzesca”, and might instead be what I’m looking for (it’s hard to tell). Oh, and just a few bundles away, the same archive has the intriguing-sounding scat. 1569: “Miscellanea, astrologia, occultismo, superstizione etc.” Really, what historian of mysteries could resist sneaking a peek? 😉

20 thoughts on “Milanese enciphered letters, call for help…

  1. Dennis on June 30, 2011 at 4:49 am said:

    Hi Nick! Just a comment in general. Have you ever contacted David Kahn? He has a web site, and it’s possible he’s studied some of this sort of thing. And what about contacting Cryptologia journal for possible contacts?

    I have a few FB friends in Italy, most likely the same ones as you, who might conceivably be helpful. it’s good to have correspondents on the spot, or as nearly as possible, like news services do.

  2. Not exactly enciphered but I think relevant to the Vms
    A Yemeni tax list of the Mamluk era found in Milan.

    Cahen, Claude and Serjeant, R.B., ‘A Fiscal Survey of the Medieval Yemen Notes ..(etc.)’ Arabica , T. 4, Fasc. 1 (Jan., 1957), pp. 23-33.
    -available through JSTOR –

  3. Laurent on July 7, 2012 at 8:59 am said:

    I see I’m not the only one studying milanese ciphers. I’m writing a thesis for my Master 2 in italian language and litterature about the work of Lydia Cerioni “La diplomazia sforzesca…” and i need some information on the author, who is she? where is she working? etc. If you have any information to share about these books and about the milanese dutchy in the 15th century in the Sforza’s court in general i’ll take it, I can share information too if you need but i’m in the beginning of my thesis…I’m french by the way…

  4. bdid1dr on July 13, 2012 at 11:44 pm said:

    I may be completely off-track, but: several weeks ago I came across a piece of art-work that portrayed one of the Sforza family Popes. In the background of that portrait painting was anoither painting that supposedly portrayed that particular Pope as being the hero that saved the Italian naval ships in the battle that took place in the harbor (Venice?Milan?).

    I hope I’m not leading you all astray!

  5. bdid1dr on July 13, 2012 at 11:52 pm said:

    Oh, I just now recall the name of the website: Rome Art Lover

    Don’t be put off by the rather “commercial” venture of the website’s tour-guide. He does a fair dialogue for each of his presentations.

  6. The subject of Aloys Meister has cropped up in the Voynich mailing list.

    Hope you don’t mind but I’ve referred everyone to this post.


  7. Mark Knowles on October 21, 2017 at 2:29 pm said:

    Nick: Another interesting blog post. I am only just starting to get to grips with the daunting task of chasing up the information that I am looking for or specifically one or two nuggets of gold. Any assistance if you have any time based on your experience would be of great value.

  8. Mark Knowles on October 31, 2017 at 11:42 pm said:

    I was googling for Milanese ciphers from the era of Fillipo Maria Visconti. I could not easily find anything, although I came back to a review I had seen before, on a different search, by Doctor Catherine Fletcher of “Carteggi degli oratori sforzeschi alla corte pontificia I: Niccolo V (27 febbraio 1447–30 aprile 1452). Gianluca Battioni,ed”. I quote from this:

    “Beginning with the death of Pope Eugenius IV in February 1447, the letters recount the process through which Sforza and Nicholas maneuvered toward their respective political triumphs of 1450: the former’s entry into Milan and the latter’s successful jubilee. These were early days for resident diplomacy in Rome, which was still not officially tolerated, though among Sforza’s representatives, Nicodemo Tranchedini (1413–81) soon came to take a central role. As with any series of diplomatic letters, this carteggio gives us a sense of the ruler’s priorities. Early on, the concern is with establishing Sforza’s position, and there is a wonderful juxtaposition of the envoy of Marcolino Barbavara’s part-ciphered dispatch suggesting to Sforza ways of encouraging “these priests” to contribute to his expenses with Sforza’s letter to the College of Cardinals, describing his desire for the health, well-being, peace, quiet, defense, and growth of the Papal States. Other correspondence underlines the importance of secrecy. One entry in a diplomatic memorandum notes that certain matters are not to be disclosed to the vicechancellor. Filippo Maria Visconti, sending a cipher to his agent in Rome in a letter a couple of months before his death, reassures the man that he will not be tasked with anything that might weigh on his conscience.”

    In this instance the letter from Filippo Maria Visconti sounds interesting to me as part of an attempt to fill in the gaps in the Milanese cipher record.

  9. Mark Knowles on November 1, 2017 at 9:01 am said:

    Nick: I have downloaded Meister. As you say there are ciphers from 1424 and 1435 which use the 4o character.

  10. Mark Knowles on November 2, 2017 at 4:45 pm said:

    Nick: Unsurprisingly it would seem that given the destruction of the Milanese records most examples of Milanese ciphers prior to 1450 are best found in amongst correspondence with other states and so a good place to look is in amongst the archives of letters in Florence, Venice, Vatican as well as others. I think some other people have carried out some of this research and hopefully they should be able to give me some idea of their findings.

  11. Mark Knowles on November 17, 2017 at 4:05 am said:

    Nick: One simple a probably very obvious thing->

    What was the procedure in practice for cipher communication?

    Presumably in person or by letter the rules of a particular cipher were agreed upon for subsequent communication or would the cipher be different for each communication and so obviously transmitted separately each time? I would imagine that there would be different cipher rules dependent on who was being communicated with, so one cipher for communicatiion witb Venice and another for communication with Savoy. Was the cipher the same both ways? i.e. messages to Savoy used the same cipher as messages from Savoy. I would guess that every say 2 years the cipher was changed. I would assume the message would have been hand transmitted by a different trusted individual each time. How would generally a messsge be intercepted, a disloyal member of staff or the physical capture of the messenger? Before the days that there was a cipher secretary would one secretary, in practice be responcible for the production of all ciphers amongst their other duties? Or would this work be spread over many secretaries for each different state one was communicating with? To what extent were cipher used for communication within a state?

    There are probably other questions to ask, but these are the first that occur to me.

  12. @Mark
    Is that a general question? Because with the VM it would not help.
    Since the cipher is useless without a book, and without a cipher, you can not read it.
    This is different from a normal conversation where information tiled back and forth

  13. Mark Knowles on November 17, 2017 at 10:53 am said:

    Peter: It is a general question which only relates to the Voynich indirectly. I am talking about diplomatic cipher communication not the Voynich itself. However it relates to my Voynich research.

  14. Mark Knowles on November 21, 2017 at 11:20 am said:

    Nick: When it comes to enciphered letters do we tend to know who wrote each letter or normally is it the case that it is written on behalf of someone without any clear about who prepared or implemented the cipher.

    Do we see->

    Your Sincercely,

    John Smith on behalf of Filippo Maria Visconti


    Filippo Maria Visconti

    So we may or may not know who had the cipher expertise.

  15. Mark: as far as I know, we almost never see the name of anyone who wrote a letter for someone else, whether enciphered or not. So this whole area remains murky, with only occasional flickers of light. 🙁

  16. Mark Knowles on December 7, 2017 at 4:18 pm said:

    Nick: What do you think the fate was of intercepted letters? So supposing a Milanese enciphered letter was captured on route to its destination then would we find the letter in the archives of the intercepting power? I wonder if this is somewhere else to look for Visconti era ciphers.

  17. Mark Knowles on December 8, 2017 at 7:53 pm said:

    Nick: The “4o” character is regularly mentioned for understandable reasons. In general to what extent are characters reused in new cipher alphabets? And to what extent are completely new characters invented each time? The reason for my question is that I am interested in seeing whether it is possible to find another distinct Voynich character in a non-Voynich text.
    I am in the process of trying to track down various Milanese enciphered letters from the letters of Marcolino Barbavara to the earlier intercepted letters of Guarniero Castiglione to the Duchy of Milan dated 1432.
    My hope is that with examples like these and with luck earlier Milanese enciphered correspondence I might find some identifiable character of feature which parallels something we see in the Voynich.
    It is true that the author could have created all the significant characters excluding the “4o” from his/her own imagination without drawing on other known characters.
    So I wonder if inventing completely new cipher alphabets is a standard thing to do or if it is very unusual. Obviously the Voynich falls into the category of very usual, but I like to believe it has some similarities to ciphers of the same time and place even if only superficial rather than technical. Do tell me what you think?

  18. Mark Knowles on December 9, 2017 at 6:39 am said:

    Nick: I wonder about the evolution of cipher alphabets. So for example a character in one alphabet may resemble a character in an earlier alphabet even though it is not the same. Obviously I am trying to establish links betweem the symbols of one cipher alphabet and another and thereby looking to see if I can establish a link between the Voynich alphabets and that of a different cipher. Again my focus is much more on purely visual similarities rather than functional similarities. Again, do tell me your thought. Thanks

  19. Mark Knowles on December 9, 2017 at 12:02 pm said:

    Nick: I should say that I don’t believe the identification of common cipher characters will necessarily make it any easier to solve the cipher. However it clearly has another value in that it helps pin down more precisely time periods and potential location.

    At the moment the “4o” character, which is also in the Croatian Glagolitic alphabet, is a loose common thread between the Voynich and Northern Italian ciphers.

    In addition, if we are honest, I don’t think we can be confident associating the “4o” with specifically Milanese ciphers.

    I am not saying that I am doubting the Milan connection or that we are dealing with a cipher, merely that the connection is more tenuous than I originally thought.

  20. Mark Knowles on December 10, 2017 at 2:59 pm said:

    Nick: A question I ask myself and perhaps you is: Why is the “4o” character the character we see in the Voynich rather than others? Was it a particularly commonly used character? Are they other similarly complex characters that were as commonly used?

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