The contents of the letter, however, had remained a mystery with historians unable to decipher it. A mysterious letter written by French emperor Napoleon Bonaparte has been decoded for the first time after 217 years using artificial intelligence (AI). The letter was sent to Auguste de Marmont by Napoleon’s stepson, Eugene, the Viceroy of Italy, in 1809. The first line is written in French, but the subsequent 24 lines consist of two-digit numbers, stray letters and invented symbols.
After spending six hours, the advanced version of the AI system that powers ChatGPT figured that the letter contains details of French and Austrian troop movements on the eve of war between France and the Habsburg Empire. Carter Church, an AI engineer at cybersecurity company SentinelOne, used OpenAI’s GPT-6 Astra system to decrypt the code and transcribe the message. “I used GPT–6 Astra to break an unsolved cipher to one of Napoleon’s generals that had gone unread for 217 years. What makes this impressive isn’t actually the codebreaking, but that Astra completed the entire multi–modal workflow in approximately 6 hours from a single image and goal,” Carter explained in a social media post. Church said he had never attempted to decode a cipher before but decided to give it a go after seeing an AI model decode a 1941 German army message.
