King George III, who ruled the country for nearly 60 years before his death in 1820, is one of the most famous disabled people in history, mainly thanks to the 1994 film The Madness of King George, which memorably brought the story of his mental health problems to a popular audience.

But what caused King George's mental illness? For many years, it was believed to be due to a genetic disorder that caused variegate porphyria. Now, however, a team of scientists from the UK and Australia have found high concentrations of arsenic in samples of the king's hair, and have suggested that it came from the medicines that he was given - sometimes by force - to 'cure' him. Arsenic, after all, was widely used as a medicine even into the 20th century, and according to medical records of the time, George was sometimes forced to take medication that would have contained up to nine milligrammes of arsenic a day - that's well below a lethal dose, but certainly enough to cause chronic poisoning and contribute to his unusually severe and prolonged periods of poor mental health.

Read more in The Scotsman newspaper. Interesting stuff.