The Prince of Wales became the first senior royal to attend Eton College when he enrolled at the prestigious Berkshire boarding school in 1995 – and in doing so, he broke a royal precedent.
The King followed in the late Duke of Edinburgh's footsteps and attended Gordonstoun School in Moray, Scotland in the 1960s.
His younger brothers, Prince Andrew and Prince Edward, are also former pupils, along with Princess Anne's children, Peter Phillips and Zara Tindall.
It's been widely reported that Queen Elizabeth II and Prince Philip favoured sending their children to Gordonstoun as it afforded the royals a greater degree of privacy than the private schools situated closer to London could.
But when it came down to Prince William and Prince Harry's education, Charles and his late ex-wife, Diana, Princess of Wales, chose Eton College instead, and it's said to be down to Charles' experiences at his boarding school.
It's been long reported that Charles did not enjoy his time at Gordonstoun and is said to have struggled to cope in the tough environment.
According to claims by Prince Harry in his memoir, Spare, Charles was "horrendously bullied".
"The most likely victims of Gordonstoun bullies, [my father] said, were creative types, sensitive types, bookish types - in other words, Pa," Harry wrote. "His finest qualities were bait for the toughs. I remember him murmuring ominously: I nearly didn't survive."
However, in a speech to launch his charity, The Prince's Trust, in 1975, Charles told the House of Lords of Gordonstoun: "It was only tough in the sense that it demanded more of you as an individual than most other schools did mentally or physically.
"I am lucky in that I believe it taught me a great deal about myself and my own abilities and disabilities. It taught me to accept challenges and take the initiative. Why else do you think I am brave enough to stand up before your Lordships now?"
In May it was announced that the King had become patron of the Gordonstoun Association, a role previously held by Prince Philip.
While William was the first senior royal to attend Eton College, there were also family connections to the boarding school on his mother's side. Diana's brother, Charles Spencer, was also educated at Eton.
To combat press intrusion while his sons were at the school, Charles struck a deal with the media where William and Harry were afforded privacy in return for limited access at photo calls. Cameras only captured the Princes on their respective first days in 1995 and 1998.