Princess Diana and Prince Charle
Princess Diana and Prince Charles were both not in good condition and cheerful mood before their royal wedding. Pictured: Prince Charles and Princess Diana at Westminster Abbey, London, for a centenary service for the Royal College Of Music on Feb. 28, 1982. Getty Images/Fox Photos

Princess Diana and Prince Charles weren't as happy and excited as other couples on the eve of their royal wedding.

Sally Bedell Smith claimed in her book, "Charles, The Misunderstood Prince," that the Prince and late Princess of Wales weren't in their best condition when their wedding was approaching. She wrote that just hours before walking down the aisle, Princess Diana reportedly had a "bulimic attack." She suffered an acute episode the night before her big day and was throwing up.

"On her wedding eve at Clarence House, Diana could hear the spectacular fireworks celebrations in Hyde Park," Bedell wrote (as quoted by The Sun). "Unknown to even her sister Jane, who stayed with her, Diana had a bulimic attack and was as 'sick as a parrot.'"

She added that just two days prior to the royal wedding, Princess Diana and Prince Charles looked cheerful at their wedding rehearsal in the majestic cathedral. In fact, the People's Princess looked demure in a high-necked dress, and the couple was in good spirits as they waved to the crowd. But another thing happened when they were out of sight.

"But in the car, Diana broke down again – 'sobbed my eyes out,' she recalled, 'absolutely collapsed'…the Camilla thing rearing its head," Bedell added.

Prince Charles seemed to feel the same. The future king reportedly spoke with his valet Stephen Barry prior to tying the knot with Princess Diana. The heir was evaluating his position.

"He did not share the exuberance on display outside the Palace," the book read. "Rather, he was in a contemplative mood. As he listened to the choruses of Rule Britannia, Charles found himself weeping."

Prince Charles and Princess Diana's marriage didn't work. They ended in divorce. According to Prince Charles' financial aid, the princess got everything Prince Charles had following their split.

"Princess Diana took every penny he had," Bignell told The Telegraph. "I was told to liquidate everything, all his investments, so that he could give her the cash. He was very unhappy about that. That's when I stopped being his personal financial adviser because he had no personal wealth left. She took him to the cleaners."

According to Bedell, when Prince Charles dispatched Michael Fawcett, his valet for 10 years, to get his belongings in Kensington Palace after their separation, Princess Diana ordered to change the locks.

"Diana loathed Fawcett, whom she regarded as an overbearing bully to those below him and a sycophantic lackey to Charles and Camilla," Bedell wrote.