FONTAINEBLEAU, France -- A secret code letter sent in 1812 by Napoleon Bonaparte boasting that his French forces would blow up Moscow's Kremlin has sold at auction for ten times its estimated presale price.

A Paris museum -- the Museum of Letters and Manuscripts -- was finalizing its purchase of the Oct. 20, 1812, document for (euro) 187,500 ($243,500), including fees. That's far above the pre-sale estimate of (euro) 15,000 ($19,500).

Auctioneers at Fontainebleau Auction House south of Paris say the letter sold Sunday is unique. It was written in a numeric code used by the French ruler to throw off would-be interceptors. Its content bared the strains on Napoleon of his calamitous Russian invasion.

One line said: "At three o'clock in the morning, on the 22nd I am going to blow up the Kremlin."