A rumour said Kaspar Hauser was the stolen heir to the throne of Baden; he was stabbed to death in 1833, and a 2024 DNA study ruled out the Baden line

Kaspar Hauser is a claimed lost heir whose claim was never proven. On 26 May 1828 a teenager appeared in Nuremberg carrying two letters, later judged to be in one hand. He said he had grown up in a dungeon. A rumour spread that he was the hereditary prince of Baden, born on 29 September 1812 to Grand Duke Charles and Stéphanie de Beauharnais. That prince officially died on 16 October 1812. The rumour said Countess Louise Caroline of Hochberg swapped him for a dying baby so her own son could inherit; her son became Grand Duke Leopold. The British Lord Stanhope took custody of Hauser in 1831 and later wrote that he had been deceived. On 14 December 1833 Hauser came home in Ansbach with a stab wound, saying a stranger had attacked him. He died on 17 December; some writers think the wound was self-inflicted. In 1996 a Munich lab found that blood on his underwear did not match Baden DNA. In the early 2000s a Münster lab found his hair a close match. In 2024 a team including Walther Parson and Turi King tested hair again. The paper in iScience found his maternal DNA did not match the House of Baden. King said, "Sadly our data still can't tell us who he was!" His gravestone in Ansbach calls him "the riddle of his time."