The dress sword carried by Napoleon Bonaparte when he staged a coup in 1799 will go under the hammer at the weekend with five other weapons that belonged to the French emperor, US auctioneers announced.
The lot, which will be put up for auction from December 3 to 5 by the Illinois-based Rock Island Auction Company, is valued at $1.5 million to $3.5 million.
The sword, with its scabbard, is the "crown jewel" of the collection, said the auctioneers, who will host the sale both in person and online.
The weapon was made by Nicolas-Noel Boutet, who was director of the state arms factory in Versailles.
After being crowned emperor, Napoleon is believed to have presented the sword to general Jean-Andoche Junot, but the general's wife later was forced to sell it to pay off debts.
It was then recovered by a London museum. A US collector was its last owner, but the man recently died, according to the auction house.
In May, France celebrated the bicentennial of Napoleon's death.
The famed Corsican is one of the most divisive figures in French history, his huge contribution to the creation of the modern state set against his imperialism and war-mongering.