These letters are simple but carry deep emotions of Prince Charles of UK.
Devastated after separating from his wife Princess Diana and her eventual death in a car accident, Prince Charles picked up his fountain pen to glut his sorrows on sheet of paper.
He wrote letters to former US President Ronald Reagan and his wife Nancy Reagan to pour out his feelings.
In one of the letters written to Nancy Reagan, Prince Charles wrote, "You'd not understand what it all means until it will happen to you, maybe that's why it is getting worse and worse. Someday, I will tell you the whole story. This is a Greek tragedy and would certainly make a very good play."
On June 4, 2017, Daily Mail released personal letters that were exchanged between Prince Charles and Reagans, which formed the backbone of their friendship for four decades. But all this ended when Nancy Reagan died last year at the age of 94.
At present, Prince William and Prince Harry are busy campaigning for issues of mental health in UK. They've started speaking openly about the death of their mother Princess Diana. While all this is going on, never-seen-before-letters from Prince Charles, their father, has been leaked to the media.
Prince Charles wrote these letters to his trusted friends - Reagans - in the US. These letters reveal that Princess Diana's death had left him emotionally drained.
On Nancy's death in March 2016, these private letters were handed over to Reagan Presidential Foundation and Library in Simi Valley, US. All of these have been part of Mrs Reagan's private collection earlier.
Prince Charles' letter reveals his emotions as he describes how Princess Diana had dazzled the dance floor at the White House Gala in 1985.
"Diana still hasn't got over dancing with John Travolta, Neil Diamond and Clint Eastwood in one evening not to mention the President of the United States as well," reports Mirror.
All these letters have been made public as a historical archive. Thanks to former US President Ronald Reagan and ex-FLOTUS Nancy Reagan.
Prince Charles admits that the death of his grandmother left him devastated. He expressed the pain in a letter of June 2002.
Even today, in the world of emails, texts and social media; Prince Charles prefers hand-written letters.