and Queen Camilla were during their recent State Visit as they celebrated their 20th wedding anniversary. While many royal fans flocked to congratulate them on social media, some can't help but think of Charles, 76, and his wedding to his first wife the late Diana, Princess of Wales.

Although the King, who was Prince of Wales at the time, did marry Lady Diana Spencer when she was just 20 years old and went on to have two sons Prince William and Prince Harry, it is well-known that he did not love her in the way he loves Camilla.

This was hinted at by one of her friends, who claimed Charles made a brutal confession to the late princess on the eve of their 1981 wedding, as Diana's friend and astrologer, Penny Thornton, who worked closely with the princess, claimed on an ITV documentary that Charles told the late princess that he didn't love her just hours before they exchanged vows.

On the ITV documentary The Diana Interview: Revenge Of A Princess, Penny said: "One of the most shocking things that Diana told me was that the night before the wedding Charles told her that he didn't love her...I think Charles didn't want to go into the wedding on a false premise.

"He wanted to square it with her and it was devastating for Diana. She didn't want to go through with the wedding at that point, she thought about not attending the wedding."

Despite this heartbreaking confession, the couple went ahead with the wedding and appeared happy for some time until hints of trouble began to show. The couple then separated in 1992 before divorcing in 1996 - a year before Diana's tragic death.

As well as having told Diana he did not love her before their large televised wedding,it was previously believed the monarch had

In Channel 5's documentary Charles and Di: The Truth Behind Their Wedding, narrator Tracy-Ann Oberman explained that "in the month before the wedding Charles had confided to one of his friends he did not yet love her. But he was sure he could."

This revelation may not come as a surprise to some as King Charles, who was Prince Charles at the time, to a young Diana.

When one journalist told the couple they looked very much in love, Diana was quick to say "of course", however Charles made a comment that seemed to shock his future wife. He laughed awkwardly, at the question before saying: "Whatever in love means".

While Charles and Diana may not have had a fairytale wedding in the end, they did appear to be on friendly terms before her tragic death. The King then remarried in 2005 to Camilla, who many believe had always been his true love.