FONTAINEBLEAU, France: A gold-encrusted sword Napoleon wore into battle in Italy was sold on Sunday for more than $6.4 million at an auction south of Paris, the auction house said. The last of Napoleon s swords in private hands, it had been expected to fetch more than $1.6 million, the Osenat auction house, managing the sale, said. Osenat did not identify the buyer, but said the sword will remain in Napoleon s family, which had put it up for sale in the first place. The emperor gave it to his brother, Jerome, as a wedding gift in 1805 - and it had remained among their descendants ever since. Applause rang out in a packed auction hall across the street from one of Napoleon s imperial castles in Fontainebleau, a town southeast of Paris where the sword was sold. The intricately decorated blade is 97 cm in length and curves gently - based on an inspiration Napoleon drew from his Egyptian campaign, auctioneer Jean-Pierre Osenat said. The sword was carried by Napoleon - who was not yet Emperor - into the battle of Marengo in June 1800, where he launched a surprise attack to push the Austrian army from Italy and seal France s victory, auction house officials said. The sword was declared a national treasure in 1978, meaning that under French law it could be sold to a foreign buyer but had to remain in France for at least five months per year. The sale ended up being a family affair. Before the auction, its joint owners were eight direct descendants of Napoleon. Strong enough for battle, the sword is uncommonly ornate - with geometric designs in gold covering the hilt and most of the blade.