Prince Charles reportedly had a heartbreaking phone conversation with Camilla before tying the knot with Princess Diana.

The Prince of Wales has always been in love with Camilla. However, the royal family didn't find her to be "aristocratic" enough for the future king, so they ruled her out. Prince Charles went on and found "virginal" Princess Diana, whom the other royals approved but Prince Charles apparently didn't love.

According to Jessica Jayne's book, "The Duchess of Cornwall: Camilla's Story and Secrets," Prince Charles called Camilla due to his concerns for the future prior to his wedding. During the call, the prince was reportedly in a "confused and anxious state of mind."

"I do very much want to do the right thing for this country and for my family – but I’m terrified sometimes of making a promise and then perhaps living to regret it," Prince Charles told Camilla.

Prince Charles was forced to propose to Princess Diana because Prince Philip gave him an ultimatum. Jayne claimed in the same book that the late Princess of Wales grew anxious about Camilla's presence in Prince Charles' life in the early days of their courtship. As such, the Duke of Edinburgh prompted his son to make a move quickly before Princess Diana's reputation would be ruined.

Prince Philip had reportedly always been more supportive of Princess Diana compared to Camilla. "Prince Philip, a man who had given up his naval career to stand in his wife’s shadow, wrote Diana a string of deeply personal letters," historian Sarah Gristwood said. "Never mind how Camilla might felt about that he was being supportive towards Diana and no one knew better than Prince Philip just how hard it was for an outsider to come into the Royal Family."

However, no matter what Prince Philip and Queen Elizabeth II did, Prince Charles just couldn't get over Camilla. In fact, Princess Diana was aware of his secret phone calls to Camilla during their holiday trips. In one of their conversations, Princess Diana heard Prince Charles talking to Camilla over the phone in his bathroom, saying, "Whatever happens, I will always love you."

According to Jayne, Princess Diana "desperately wanted [her marriage to Prince Charles] to work, I desperately loved my husband and I wanted to share everything together." In fact, Princess Diana confronted Camilla one time where the latter asked the former what more she wanted because she already got everything. Princess Diana only responded with, "I want my husband."

Prince Charles and Camilla Parker Bowles
Prince Charles made a heartbreaking phone call to Camilla Parker Bowles before he married Princess Diana. Pictured: Prince Charles and Camilla in the White Drawing Room at Windsor Castle after their wedding ceremony, April 9, 2005 in Windsor, England. Getty Images/Hugo Burnand