In 'Diana, Our Mother: Her Life and Legacy,' the two brothers come together for their first-ever joint interview about Princess Diana.
Harry describes his mother as 'one of the naughtiest parents.'
Kate Middleton, Princess Charlotte and Prince George also attended the private memorial service on Saturday in England.
ET has insider details on how the royals will remember Diana on what would've been her 56th birthday.
Prince William, Prince Harry and Kate Middleton to Rededicate Princess Diana's Grave on Her Birthday
The royal recently opened up about his tumultuous relationship with his position as a member of the British Monarchy.
The royal opened up in a new tell-all profile with 'Newsweek.'
The royals are speaking out on the family tragedy in a new BBC documentary.
The 34-year-old royal got candid about his mother's death in the latest issue of British GQ.
The 34-year-old royal is getting candid about his mother nearly 20 years after her tragic death.
The Duchess of Cornwall recalled the media storm that kept her out of the public eye for 'about a year.'
The Duke of Cambridge, and his brother Prince Harry, honored their mother on Thursday in London at the inaugural Legacy Awards.
Prince William and Prince Harry presented the 'Diana Award' on Thursday to 20 people.
EXCLUSIVE: New Princess Diana Special Delves Into Her 'Passionate' Love Life and Her Greatest Fear
