An unsolved encryption from the 15th century

In 1497, the future Emperor Maximilian I wrote a short encrypted message under an otherwise unencrypted letter. Can a reader solve this cryptogram?

Deutsche Version

For today’s blog article, I had to take another history lesson. It’s about Maximilian I (1459-1519), an important ruler of the early modern era.

Quelle: Wikimedia Commons

As one learns on Wikipedia, Maximilian came from the House of Habsburg and was Roman-German emperor from 1508 until his death. He was considered a forward-looking and modernizing ruler and was nicknamed “the last knight” because he embodied the ideal of the old Burgundian chivalry, which had already dwindled by then.


A letter from 1497

Last week I received an email from Zoë Maula, a Dutch woman. Zoë studied Japanese studies in Leiden, but she is also interested in the history of the Netherlands in the 15th century.

During her research, Zoë came across a letter from 1497, signed by Maximilian I. Here is a scan of it:

Quelle/Source: Archives départementales du Nord

The letter, otherwise written in plain text, contains a short encrypted message to the right of the signature:

Quelle/Source: Archives départementales du Nord

Unfortunately, Zoë did not manage to solve this cryptogram. She therefore turned to Satoshi Tomokiyo, who thankfully referred her to me.


Another Cryptogram

During her research, Zoë also came across a document of Maximilian I dated March 10, 1495, which is mentioned in a book. This, too, contains a coded text:

Quelle/Source: Public Domain

It could be the same encryption method.


Solution approaches

The first encrypted message of Maximilian I consists of only about 14 symbols. So it is a microcryptogram (I have used the term “minicryptogram” so far, but “microcryptogram” seems more appropriate to me). A microcryptogram is often difficult to solve, especially if – as is the case here – the letters or symbols hardly repeat.

In front of the encoded text the Latin word ”Scio” (“I know”). This could give a hint to what follows.

The second cryptogram is a bit longer. Perhaps the total of almost 40 symbols is sufficient for a frequency analysis.

Regardless, it seems possible that such an important personality as Maximilian I left behind more cryptograms or other helpful information. Perhaps a reader can help further. Zoë Maula and I are looking forward to corresponding hints.

Hint: The original version of this article did not include the second cryptogram.

If you want to add a comment, you need to add it to the German version here.

Further reading: Wie ein Mathematiker einen Geheimcode aus dem Nachlass von US-Präsident Jefferson knackte


Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.