'The Lost Prince': Why the Queen's uncle was shut away from the public.

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He was born into royalty in 1905. The youngest child of King George V of the United Kingdom and Queen Mary. He was a Windsor. Sixth in line to the British throne. Brother to Prince Edward and Prince Albert, two men who would both later become King.

But His Royal Highness Prince John is also known by another title. The Lost Prince.

For as he approached his teenage years, the young Wales vanished from the public eye. Confined to a cottage in a secluded corner of Sandringham Estate, in Norfolk; away from Royal duty, away from school, friends, even family, all due to something far beyond his control.

Epilepsy.

Prince John was diagnosed with the condition in 1909, and though he reportedly spent his early years in relative normalcy, his seizures became more frequent and more severe as he got older.

By 1915 he was sent away to live at Wood Farm, Sandringham, under the care of his governess Charlotte Bill. By 1916, he rarely left the estate.

Some have speculated the King and Queen confined him there due to fear a public 'episode' would cause the family embarrassment, but as the British Epilepsy society told The Mirror, the monarch's decision was far from unusual.

"At that time, people with epilepsy were put apart from the rest of the community," a spokesperson said. "They were often put in epilepsy colonies or mental institutions. It was thought to be a form of mental illness."

There is speculation that Prince John may have also lived with autism based on descriptions of his behaviour, though such a diagnosis didn't exist at the time.

It was Prince John's station - and the devotion of Bill - that spared him from prevailing forms inhumane treatment. Though yes, he was removed from public and family life, his mother, Queen Mary, broke Royal protocol and allowed the children of estate workers - commoners - to visit Wood Farm and play with her son.

His grandmother, Queen Alexandra, also maintained a garden on the estate for his enjoyment, which, according to Town And Country, gave Prince John "some of the happiest moments" of his too short life.

The young Prince died in his sleep on the evening of January 18, 1919, following a massive seizure.

Letters from his brother, Prince Edward, which were put up for auction in 2015 revealed that though the Royal family mourned the 13-year-old, the death was also a relief.

"He's been practically shut up for the last two years anyhow no one has even seen him except the family and then only once or twice a year and his death is the greatest relief imaginable or what we've always silently prayed for," Prince Edward wrote, according to The Telegraph.

"No one would be more cut up if any of other three brothers were to die than I should be, but this poor boy had become more of an animal than anything else and was only a brother in the flesh and nothing else."

The Daily Mirror broke the news to the kingdom the following day, and reported that "when the Prince passed away his face bore an angelic smile". According to a Channel 4 documentary about Prince John, the article was the first the wider public knew of Prince John's epilepsy.

He was buried at Sandringham Estate.