The royal family was unwelcoming of the arrival of Camilla Parker Bowles to the Royal Palace, and it didn't help that Prince Charles delayed his engagement to his now longtime partner.
Prince Charles and Camilla announced their relationship in 1999, which was two years after Princess Diana's tragic death in Paris. Because of the incident, Camilla struggled in winning the approval of the Queen, citizens, and Royal watchers as Prince Charles' new partner.
However, while the approval of the royal family was certainly a big deal, the real reason why Prince Charles and the Duchess of Cornwall delayed their marriage was mainly because of the "sensitivity towards" Prince William and Prince Harry.
As excerpted in the 2005 book "The Firm" by Penny Junorz, a royal biographer, Prince Charles and Camilla did not want to force Prince William and Prince Harry to meet and accept a stepmother wholeheartedly before they had fully grown up. They also took note of the sudden death of Princess Diana, which affected the two princes emotionally and mentally.
"Accepting Camilla as a fixture in their father's life has been difficult for them," Junor stated in the book.
Princes William and Harry knew that Camilla caused the grief and misery of their late mother and how Princess Diana became an "extra" for so long in the veiled relationship of the Prince Charles and the now Duchess of Cornwall.
That fact alone made it even harder for Camilla to be accepted by the Royal family.
In addition, Queen Elizabeth offered nothing but disapproval towards their relationship. According to Tom Bower's biography "Rebel Prince: The Power, Passion, and Defiance of Prince Charles," the Queen reportedly called Camilla "that wicked woman" and showed so much displeasure towards her.
Things even got worse to the point that during the celebration of Prince Charles' 50th birthday, Queen Elizabeth II and Prince Philip refused to attend and chose to stay away. Prince Charles' once-adulterous relationship with Camilla created more space between him and his family.
Time went by and the Royal Family got over from Princess Diana's death. It also allowed each member to accept Camilla little by little.
The Queen received an invitation to attend an event in Highgrove, where she knew Camilla would also be. The Queen still went to the event, and royal watchers considered it as a sign that she finally approved her son and Camilla's relationship.
On April 9, 2005, Prince Charles and Camilla finally tied a knot at Windsor Guildhall. They also had a service at St. George's Chapel to receive a special marital blessing since, at the time of their engagement, the Church of England could not support second marriages if a spouse was still living (which was the case of Camilla's ex, Andrew Parker Bowles).
After all the things that happened, Prince Charles and Camilla finally got the happy ending -- an official marriage blessing and approval from the Royal Family -- they waited to receive for six long years.