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.
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.