Summary
Artificial intelligence has helped decode a secret letter that was written more than 200 years ago during the time of French Emperor Napoleon Bonaparte.
The coded letter was written in 1809 and contained military information. AI engineer Carter Church used an AI model to study an old image of the letter and help solve the code.
The decoded message gives historians a better look at how Napoleon’s forces communicated during wartime.
What Happened?
The letter was written using a secret code to protect important military information.
It was sent by Eugène de Beauharnais, Napoleon’s stepson and the viceroy of Italy, to French Marshal Auguste de Marmont.
The letter contained information about the positions of French and allied armies.
At that time, military letters could be intercepted by enemies. Using a code helped protect the information if the letter fell into the wrong hands.
How Did AI Decode the Letter?
AI engineer Carter Church used an AI model called GPT-6 Astra to study the coded letter.
According to the report, Church provided the model with an image of the letter and a prompt. The AI worked on the problem for about six hours.
The original image was not high quality. It was a low-resolution scan published in a French military journal in 1969.
The letter contained around 1,300 symbols, with about 155 different symbols being used.
A Previous Code Table Helped
The AI did not solve the mystery completely from nothing.
During its research, the model found an older table created by cryptology historian Daniel Tant. The table explained the meaning of 33 symbols, covering about one-third of the coded letter.
The AI then used this information to work out the meaning of the remaining symbols and translate the message.
This shows why historical research and AI can work together. Existing research provided important clues, while AI helped connect those clues and process the coded document.
What Did the Letter Say?
The decoded letter mainly discussed the positions of troops and military commanders.
It also told Marmont not to be afraid of the opposition he might face.
However, historians said the translated message did not reveal a completely unknown secret about Napoleon. Much of the information was already known from other historical correspondence.
Why Is This Important?
The discovery shows one possible way AI can help historians study old documents.
Many historical documents are difficult to understand because they may contain:
- Secret codes
- Old handwriting
- Damaged pages
- Unknown languages
- Unclear symbols
- Poor-quality images
AI could potentially help researchers study some of these documents faster.
Researchers also suggested that similar methods could be useful for studying other historical documents and old writing systems.
AI Did Not Replace Historical Research
An important point is that AI was not working completely alone.
Researchers had already studied the historical documents and created useful information about the code.
The AI was able to use this existing research and connect it with the coded letter.
The result was also checked by people familiar with cryptography and history. The solved letter has since been listed as solved by a website that tracks historical ciphers.
Could AI Help Decode More Historical Documents?
Possibly.
Researchers believe AI could be useful for studying other difficult historical documents, especially those containing unknown writing, old handwriting or codes.
There are many historical documents that researchers have not been able to study fully because solving them can require a large amount of time and specialist knowledge.
AI could become another tool that researchers use to investigate these documents.
However, AI-generated results still need to be checked carefully, especially when historians are working with documents where the correct answer is not already known.
Conclusion
AI has helped researchers decode a 217-year-old coded letter connected to Napoleon’s military communications.
The achievement shows how modern AI can be used with existing historical research to study documents from the past.
The decoded letter may not reveal a completely new secret about Napoleon, but the work demonstrates how AI could help researchers investigate other difficult historical documents in the future.
Sources
- Live Science — Report on the AI-assisted decoding of Napoleon-era
- cipherCarter Church — Research and decoded letter
- Cryptiana — Historical cipher records