The royal and the former First Lady met during a his visit to the White House in May 1981, just two months before Charles’s wedding to Princess Diana. He visited again in 1985, along with Diana. (It was on this trip that Diana had her famed dance with John Travolta.) After the trip concluded, they kept up a correspondence, which endured until Reagan’s death last year.
In one of these many letters, Charles shared details about the downfall of his marriage to Diana, likening it to a “Greek tragedy.”
“One day I will tell you the whole story,” he wrote in the letter, dated June 21, 1992. “It is a kind of Greek tragedy and would certainly make a very good play!”
“It is so awful,” he continued. “Very few people would believe it.”
The letter was written at a time when his marriage to Diana was on the brink of collapse — they separated six months later, in December 1992. He said that the situation kept getting “worse and worse,” and felt isolated in his unhappiness.
“No one can really understand what it all means until it happens to you, which is why it all keeps getting worse and worse.”
Charles also said that he had taken to reading classic literature as a distraction from the headlines about his marriage. He said he hoped it would make him “wiser and more knowledgeable.”
In an earlier, less angst-filled letter, written after his 1985 visit with Diana, he spoke of how much she enjoyed the visit to the White House.
He said: “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!”
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The letters are now the property of the Ronald Reagan Presidential Foundation and Library in Simi Valley, Calif., where they were handed over after Nancy Reagan’s death on March 6, 2016. The library confirmed their authenticity to PEOPLE.
The story of Charles and Diana’s ill-fated marriage is set to hit the small screen next year with the second season of Feud. Not quite a play as Charles himself had originally envisioned — but perhaps the contemporary version!