A two-cornered or bicorne hat that belonged to French emperor Napoleon Bonaparte was sold to a South Korean bidder for €1.9 million at auction near Paris.

Jean-Pierre Osenat of the Osenat auction house in Fontaine-bleau said the buyer acquired the black felt hat in a sale of Napoleon-era items from the collections of the Prince of Monaco.

The two-cornered hat was a trademark of Napoleon, who wore it athwart, the two points aligned with his shoulders.

“Everybody at the time wore that kind of hat one way, but Napoleon wore it the other way so that everybody would recognise his silhouette on the battlefield,” said the auction official.

During the 15 years of his reign at the start of the 19th century, Napoleon went through about 120 hats.

Osenat said only around 20 surviving items had been authenticated as belonging to the emperor, most of which are in museums.

The hat went for nearly five times the €400,000 it had been expected to fetch at the auction, where about 1,000 other pieces of Napoleon memorabilia from the Monaco collection were sold over three days.