The French government has classified them as national treasures, placing a ban on their export. The export ban certificate issued by the French culture ministry’s national treasures commission initiates a 30-month period during which the government can make a purchase offer to the new owner, who has the right to refuse. However, a cultural property classified as a national treasure can only leave France temporarily and must be returned.”Being classified as a national treasure gives an incredible value to the object,” said a representative of the Osenat auction house.Napoleon memorabilia is highly sought after by collectors, with one of his famous “bicorne” black cocked hats selling for 1.9 million euros in November.Following his abdication, Napoleon was exiled to the island of Elba off the Italian coast. He later made a dramatic return to France, but his career ended definitively with his defeat at the Battle of Waterloo in 1815. Napoleon spent his final years in exile on the island of St Helena, where he died six years later.