The famed French general wrote the correspondence in numeric code to throw off potential interceptors, and boasted that his forces would blow up Moscow’s Kremlin, the Associated Press reported.
The sale was being finalized Sunday by Paris' Museum of Letters and Manuscripts. The letter's final price was far above the original estimate of $19,500.
The letter, written to Foreign Minister Hugues-Bernard Maret during Napoleon's ill-fated invasion of Russia, begins: "On the 22nd at 3am I will be blowing up the Kremlin," BBC News reported.
It also reveals Napoleon's frustration with his military campaign. "My cavalry is in tatters, a lot of horses are dying. Make sure we buy more as soon as possible."