Napoleon secret code letter: 'I'll blow up the Kremlin'

A French auction house is to sell off an encrypted letter written by Napoleon Bonaparte, in which he vowed to burn down the Kremlin.

The missive was sent on 20 October 1812, the day after the emperor ordered his army to leave Moscow following the ill-fated French invasion of the city.

"He wanted to give some power in this letter by saying I'm still there and will blow up the Kremlin," said auctioneer Jean-Christophe Chataignier.

Claire Brennan reports.