AI helps decipher Napoleon-linked letter revealing troop positions and strategy

An 1809 coded letter linked to Napoleon Bonaparte has been deciphered after remaining unread for 217 years. Carter Church, an engineer at SentinelOne, used AI to interpret the handwritten symbols and numbers, revealing military intelligence and advice for General Auguste de Marmont during rising tensions with Austria.

The message, sent by Napoleon’s stepson Eugene, listed the positions and strength of French and allied forces, including 80,000 French troops near Bayreuth and 60,000 near Ulm and Donauwörth. It said Austria was threatened from several directions and urged Marmont not to be intimidated despite his isolated position in Dalmatia. Church said the AI completed the work in six hours, starting from a single image.