Napoleon's Secret Letter Went 217 Years Without Being Cracked, But ChatGPT Decoded It In A Few Hours
In March 1809, Napoleon Bonaparte sent a secret letter to one of his generals, Auguste de Marmont. Almost the whole letter was written in code. Only the first line was written in normal French.
The next 24 lines explained where the French army and its allies were located. Napoleon used made-up symbols, numbers, and letters to hide the information. For 217 years, nobody could work out exactly what the letter said.
Recently, an AI engineer named Carter Church used ChatGPT to decode the letter in just six hours. He used OpenAI's GPT-6 Astra and gave it a picture of Napoleon's coded letter along with just one instruction.
Interestingly, Carter said he had not originally planned to decode Napoleon's letter. He became interested after reading about Carter Leffen, who had managed to decode a German Army Enigma message from 1941. That message had remained a mystery for decades. Leffen also used GPT-6 Astra to help him, and it took about 10 hours to solve the code.
Carter explained in a post on X that the most impressive part was how Astra could handle different kinds of tasks. He said the code itself was not especially hard. Experts who study secret codes could probably have solved it if they had enough time and energy. The difficult part was reading the handwritten message, copying down the symbols, organizing the information, translating the text, and finally breaking the code. This required several different skills.
Carter also said that every field of study has a long list of small, unsolved problems that experts are too busy to work on. He believes that more of these problems will be solved by people who are not experts in those fields but are simply curious enough to try.
As for what Napoleon's letter actually said, the Austrian Empire was preparing to fight him. Austria had spent years building an army for a future war against Napoleon.
Napoleon knew that Austria was getting ready to attack. He needed to contact Marmont because Marmont commanded some of his best soldiers and was stationed in the area now known as Croatia.
Napoleon wrote the letter in Paris. He told Marmont that when he received the order to march, he should not let himself "be intimidated by a few troops or a gathering of rabble." In other words, Marmont should not be afraid of a small group of enemy soldiers or a disorganized crowd.
wowinside - stock.adobe.com - This is an illustration of Napoleon fighting at Waterloo. It is only meant to help illustrate the story and is not a real picture of Napoleon.
Marmont followed the orders in Napoleon's letter. In the end, Napoleon and Marmont defeated Austria and won the Battle of Wagram.
After the victory, Marmont was rewarded with the important military title of Marshal of the Empire. However, Marmont later betrayed Napoleon when enemy Allied armies were closing in on Paris.
Without telling Napoleon, Marmont secretly made a deal with the commanders of the enemy armies. He then ordered his 12,000 soldiers to march into the middle of the enemy forces and surrender.
After more than 15 years of fighting, Napoleon no longer had anyone left to support him. He had no choice but to give up his throne. Napoleon had trusted these men to protect France and help him remain in power, but they betrayed him instead.
You can read Carter's full explanation of how he decoded Napoleon's letter here.