Whilst the black beaver hat was the star of a sale of Napoleonic memorabilia it was only expected to fetch between 600,000 and 800,000 euros.
In his lifetime Napoleon wore over a hundred of the uniquely shaped bicorne hats.
A French industrialist spent more than fifty years assembling the collection before he died last year.
Other exceptional items on sale from Jean-Louis Noisiez’s collection included a silver plate looted from Napoléon’s carriage after his defeat at the Battle of Waterloo in 1815.
Also on auction was a vanity case he owned, with razors, a silver toothbrush, scissors and other personal belongings.
A new film, simply called "Napoleon," by British director Ridley Scott is opening in cinemas across Europe this week.