PARIS: A rare letter in English written by Napoleon Bonaparte — and replete with errors — fetched 325,000 euros ($406,445) at an auction Sunday in Paris.

The one-page letter , dated March 9, 1816,penned by Napoleon during his post-Waterloo exile on the South Atlantic island of Saint Helena, was one of just three known in the world, said auction house Osenat.

Addressed to the Count of Las Cases, Napoleon's companion in exile, the letter was acquired by the private Museum of Letters and Manuscripts in Paris and originally estimated to fetch just 60,000 to 80,000 euros.

In his “Memorial of Saint Helena”, Las Cases wrote about how Napoleon began in March 1816 to correspond with him in English in order to practise the language of his jailers that he had began learning a few weeks earlier.

The Count also wrote in particular about the auctioned letter, saying: “The emperor did not sleep that night -- during his insomnia, he decided to write me a new letter in English. “He sent it sealed to me, I corrected his errors, and replied to him, in English also, by mail.

“He understood the letter, and that convinced him of his progress and proved to him that he could, completely, correspond in his new language.”Despite Las Cases encouraging words, Napoleon's writing required some guesswork.

For instance, in one passage, he wrote: “He shall land above seven day a ship from Europe that we shall give account from anything who this shall have been even to day of first january thousand eight hundred sixteen.”

Napoleon was referring to a ship from Europe that would dock in seven days, bringing news on what has happened since January 1, 1816.

After his defeat to the British at the 1815 Battle of Waterloo, Napoleon was imprisoned and then exiled to Saint Helena where he died in 1821 age 51.