▶ Watch Video: At a time of family turmoil, Princes William and Harry commemorate Diana at Kensington Palace

London — In life, Princess Diana broke the mold for what it meant to be a modern royal, a legacy that still endures, 24 years after her death. Thursday would have been Princess Diana‘s 60th birthday. To mark the occasion, her two sons, Prince William and Prince Harry were to unveil a statue in her honor outside of Kensington Palace, but the spotlight is on the princes’ troubled relationship.

Following Harry and wife Meghan’s decision to step back from royal duties last year, and then to publicly criticize the royal family in a candid interview with Oprah Winfrey — Harry’s growing rift with his brother Prince William was laid bare.

“It’s love against duty. It’s William defending the monarchy and Harry defending his wife,” Robert Lacey, author of “Battle of Brothers” said.

Diana’s deep commitment to humanitarian work was amplified not only by her dazzling presence but with her ability to connect with people. When she died, at the age of 36, the outpouring of grief for the “People’s Princess” was unlike anything the monarchy had seen before.

The images of her two young sons, then just 12 and 15 years old, broke hearts with every step they made on the long walk behind their mother’s casket. It would be another funeral, for their Grandfather Prince Phillip in April, that briefly reunited the brothers for the first time since their differences came to light — side by side again, but reportedly still not in step with one another.

As William, Harry, and the world reflect on what would have been Princess Diana’s 60th birthday, her legacy not only endures, but continues to shape the royal family.

“The row and interest over the boys, William and Harry, has rather obscured the fact that this unveiling of a statue to Diana, the royal rebel of 20, 30 years ago, is a deeply significant event. It’s a recognition of the changing style of the British monarchy that this outreach of Diana, this common touch, this love affair, flirting with the media, is now mainstream for the royal family,” Lacey said.