It's been 22 years since they lost their mother in a tragic car crash that left the world in mourning.
Now, Princes William and Harry have been rocked by fresh allegations about Princess Diana's passing, with a new podcast Diana: Case Solved alleging the princess, then just 36, may have been killed at the hands of their own father.
The creators of the controversial podcast claim they have new evidence – diary entries, letters, recordings and eyewitness testimony – suggesting Diana's tragic death in Paris on August 31 may have been the result of careful planning on the part of her husband Prince Charles, 70, whose affair with his now-wife Camilla, Duchess of Cornwell, was well known at the time.
Conspiracy surrounding the heartbreaking death of the Princess of Wales has been rife for years, with a letter Diana sent to her butler Paul Burrell revealing she may have felt at risk.
"This particular phase in my life is the most dangerous. My husband is planning 'an accident' in my car, brake failure or some serious head injury in order to make the path clear for him to marry Tiggy [William and Harry's nanny]. Camilla is nothing more than a decoy so we are being used by the man in every sense of the word."
WATCH: The heartbreaking way Prince Harry dealt with his mother's death. Story continues after video...
The provocative podcast, which will likely leave William, 37, and Harry, 34, lost for words, comes as an alleged witness to the crash spoke out for the first time late last week.
"She was told she'd been in a terrible car crash and to lie still," the witness, who is living under an assumed name in France, told US magazine Globe.
"Her eyes narrowed and she whispered, 'He's killed me! That bloody bastard has killed me. Just like he said. Now what will happen to my boys...' and she drifted off."