Prince Charles and Princess Diana
Prince Charles reportedly found it difficult to deal with Princess Diana. The Princess of Wales Diana, Princess of Wales attend a centenary service for the Royal College Of Music on Feb. 28, 1982 at Westminster Abbey, London. Fox Photos/Hulton Archive/Getty Images

Prince Charles and Prince Diana divorced in 1996 but prior to ending their marriage, the couple went through a tumultuous break up that reportedly took an emotional toll on the Prince of Wales.

According to the book “Prince Charles Biography: The Life of the Prince of Wales and Future King of England,” the Prince of Wales and Princess Diana’s marriage reached its breaking point during a visit to South Korea in 1992.

Jessica Jayne, the author of the 2012 biography, revealed Diana could “barely conceal the true nature of their deteriorating marriage.”

On their flight back to the UK, Charles reportedly asked Diana for a legal separation and she agreed. However, when the time came to end their marriage, the Princess of Wales allegedly made things difficult for her husband.

“Every time they and their advisers met, the negotiations would end in slammed doors, shouting and tears. Charles went through this in agony,” the writer explained.

In a previous interview with Vanity Fair, Lady Pamela Hicks claimed Princess Diana was “spiteful” and “really unkind” to Prince Charles.

While friends of the future King encouraged him to attack Diana in the press, Charles remained silent. “Some of his friends saw this as the behaviour of a gentleman,” Jayne shared.

Despite his decision, Princess Diana continued to give Charles a hard time throughout their divorce negotiations. “He went through mental anguish every time he met Diana because of the sheer unreasonableness of her behaviour.”

A year following their divorce, Diana, Princess of Wales died in a tragic car accident.