Prince William just celebrated his 40th birthday. A big day in which he received congratulations from all over the world, for which he nonchalantly thanked him on Twitter. But the round birthday should have a bittersweet note for the prince, who will one day ascend the throne after his father Prince Charles. Because his beloved mother Lady Diana, who died in a car accident in 1997, cannot celebrate his special day with him. We remember his heartbreaking promise to his mom that William couldn't keep.
The divorce war sapped Lady Diana

It will soon be the 25th anniversary of the tragic death of Diana, also known as the "Queen of Hearts". Unforgotten are the pictures from her funeral, in which William, then only 15, and his younger brother Harry can be seen chasing after her coffin.
Diana's former butler, Paul Burrell, recalled a touching mother-son moment in his book "A Royal Duty" shortly before her accident in 1997. At that time, she and Charles were just getting divorced. The divorce war wasn't just about money, it was also about Diana's title of Her Royal Highness. The mother of the two princes did not want to lose it. Even Queen Elizabeth II, who has not always had a good relationship with her daughter-in-law, spoke out in favor of it. But Charles didn't want that.
Don't worry mummy
Loss of her title would have meant Diana had to follow normal royal rules. She should have curtsied in front of her prince sons. In addition, her close relationship with her children would have been in jeopardy.
In the end she actually lost her title but remained part of the Royal Family. When William, then 14, found his sad mother, he promised her encouragement, her butler at the time recalled: "She told me how he sat down with her one night when she was upset about losing her title was, put his arms around her and said, 'Don't worry mummy. I'll give it back to you one day when I'm king.'”
William can no longer keep his promise
Her son's sweet promise may have helped the dejected Diana. But just a year later, William's mother died in a tragic traffic accident in Paris.
Today Diana would be 60 years old. Her son William is second in line to the British throne and would certainly have done anything to keep his promise to his mother. On a day like his milestone birthday, his thoughts must have been with Diana.