The deaths of well-loved figures and people of legend from history tend to be exaggerated somewhat.

Take for example Grigori Rasputin, who – according to popular belief and the song by Boney M – was slipped poison inside his wine and cake, before merely getting up and eating more cake and wine. At this point, he was said to have been shot in the heart, but carried on walking around until he was finally drowned.

Quite why this account has taken hold in collective memory is bizarre, given that this was the account of his assassin Yussupov, who had merely shot him and made up the rest in his memoir, likely in order to make it sound more heroic than "he came in and I shot him with a gun".

Nevertheless, "he was shot" doesn't fit as neatly into Boney M's catchy rhyming structure, and historical accuracy was sacrificed in order to create a banger, so now that's the version of events we're stuck with.

Genghis Khan is subject to many rumors surrounding his death, though none of them have been cemented by a catchy tune. Khan, founder and brutal ruler of the Mongol Empire which became the largest continuous empire in history, died in August 1227. Little is known for sure about his death, and he was buried in an unmarked grave, possibly 20 meters (65.6 feet) deep if burial practices for Xiongnu kings were followed, making locating his body for physical investigations (or even grave-robbing) near impossible.

Stories of his death suggest he died from injuries following a fall from his horse, during the battle with Chinese forces, from an infected arrow wound, and even that he died of blood loss after being castrated by a Tangut princess.

"All these legends were most likely created at a later stage and failed to take into account – or even willingly ignored – an accepted historical fact," researchers from Flinders University in Adelaide write in a study published in the International Journal of Infectious Diseases. "Namely that Khan’s family and followers were instructed to keep Khan’s death as their most hidden secret, since it happened at the wrong time when the Mongols were at the vital stage of their desired conquest of Western Xia, the empire against which they had been fighting for over 20 years."

The team wanted to explore Khan's death from a historico-medical perspective. In The History of Yuan, the researchers write, it's said that Khan felt unwell and had a fever between August 18 and August 25, 1227. 8 days after onset, he was dead.

Previous research speculated that he had died of typhoid, though the new research argues that no other symptoms associated with the disease – such as vomiting and abdominal pain – were mentioned.

They argue that "given the general circumstances of the disease gripping his army as early as 1226, suggest a more reasonable conclusion and retrospective diagnosis, that of plague, a most ancient, history-changing and still present disease", adding that the "vague terminology used to describe the king’s symptoms and the duration of the illness make it more reasonable to opt for bubonic plague".

Though more fanciful and heroic deaths have been ascribed to the legendary figure, the team stress that historians need to take into account pandemic diseases when looking at big historical figures, "rather than trying to assume particular, exceptional causes of death."