Prince William's mother Princess Diana (†36) died when he was only 15 years old. One year before her death, the heir to the throne made a heartbreaking promise to his mother that he could not keep before Diana tragically died.
Prince Charles and Princess Diana: Dispute over a title
In December 1992, Diana and Prince Charles separated. Nevertheless, their divorce was not final until 1996, four years later. One reason for this was the many negotiations about money and especially about Diana's title.
Diana wanted to keep the the title "Her Royal Highness", which Queen Elizabeth II is said to have conceded. Allegedly, Prince Charles had opposed the decision of his mother however and wanted to prevent Diana keeping the title.
Without the title, Princess Diana would have had to obey certain rules which everyone who does not belong to the British royal house has to follow. So she would always have had to make a curtsey in front of her own sons and would have lost any formal connection to Prince William and Prince Harry.
Prince William's promise to Princess Diana
In his revealing book, A Royal Duty, royal author Paul Burrell describes how William tried to cheer up his mother during these difficult times:: "She told me how he had sat with her one night when she was upset over the loss of HRH, put his arms around her and said, 'Don’t worry, Mummy. I will give it back to you one day when I am King.'"
Just a year after the divorce was finalized, the 'Princess of Hearts' died in a car accident leaving her two sons behind. To this day, Prince William and Prince Harry do everything they can to keep their mother's legacy and memory alive. At Prince Harry's wedding, for instance, Princess Diana was honored several times.