The tragic death of Princess Diana in 1997 left the world in shock, and for her sons, Prince William and Prince Harry, it marked the beginning of a lifelong journey of responsibility, loss, and public scrutiny. Now, decades later, one of Diana’s former private secretaries, Patrick Jephson, has opened up about the “crucial warnings” the brothers were left with after her passing, emphasizing that lessons from her life remain as relevant today as they were over 25 years ago.

Jephson, who worked closely with Diana during her final years, spoke to PEOPLE, highlighting that Harry, 40, and William, 43, along with their advisors, could glean invaluable guidance from revisiting their mother’s life and example. “If they study Princess Diana’s life carefully — and I hope they often do — William, Harry, and their advisors will know that she left them many good examples to follow and also a few important warnings to heed,” Jephson said.

He elaborated that the privileges of royalty are not simply inherited, but must be earned through self-sacrifice, dedication, and public service. “Public affection and the rich rewards of royalty must be earned with self-sacrifice and service. Diana’s life serves as a blueprint for balancing private grief with public duty, and her example is a reminder that true respect cannot be commanded; it must be won,” Jephson explained.

The former secretary stressed that Diana’s guidance continues to resonate with her sons even after her untimely death in a Paris car accident at the age of 36. “I’m sure they are grateful that every day she can still guide, comfort, and inspire them along the difficult path they were born to follow,” he added.

Diana’s Role as Peacemaker

Adding to the perspective, royal biographer Andrew Morton weighed in on the current tensions between William and Harry, suggesting that Diana would have actively tried to mediate the growing rift. “Diana always used to say she had two boys for a reason — the younger would be there to support the older in the lonely task as future King,” Morton told PEOPLE.

He lamented the breakdown of the once-close relationship between the brothers, recalling the playful and protective bond they shared as children and young adults. “We all remember the days when Harry and William were joshing with one another, and it all seemed set for their relationship and the future — that Harry, as Diana always used to say, would be William’s wingman. It’s a great loss for the monarchy,” Morton remarked.

Experts argue that the absence of Diana’s stabilizing presence has been felt keenly in the years since she passed. The Princess’s empathy, intuition, and ability to mediate difficult situations would have been invaluable in guiding her sons through conflicts, both personal and public. Observers note that her warnings — to exercise caution, to value humility, and to embrace duty — are lessons that remain unheeded by the estranged siblings, contributing to a feud that continues to make headlines.

Lessons from a Life Well-Lived

Patrick Jephson emphasized that careful study of Diana’s life offers more than just emotional guidance. “William and Harry, by looking closely at Diana’s choices and her relentless commitment to causes she believed in, would understand the importance of using their position for good, rather than personal gain,” he said.

Diana’s life was marked by her tireless charitable work, her openness in addressing social issues, and her courage in challenging royal conventions. These examples, Jephson argues, provide both inspiration and warning: to succeed as a royal in the public eye, one must combine compassion with discretion, dedication with humility, and personal sacrifice with service to others.

The former secretary also stressed that the brothers’ advisors have a key role in interpreting and applying these lessons. “The right counsel is vital. It’s not just about knowing what Diana would have wanted, but translating that guidance into daily decisions that reflect integrity, commitment, and empathy,” Jephson noted.

The Althorp Estate and Age-Old Traditions

While Diana’s sons navigate personal and familial tensions, other aspects of royal tradition continue to underscore the complexities of legacy and inheritance. Reports indicate that neither William nor Harry will inherit Althorp Estate in Northamptonshire, where Diana was raised and now rests. The estate, following centuries-old male primogeniture rules, will pass instead to Diana’s nephew, Louis Spencer, Viscount Althorp.

Under this system, aristocratic titles and holdings are transferred to the eldest male heir, rather than the firstborn child, regardless of gender. Louis, who has three elder sisters — Lady Kitty, Lady Amarilla, and Lady Eliza Spencer — is next in line for the estate, highlighting how traditional rules continue to shape the royal family and its extended relatives.

Reflections on the Monarchy’s Future

The estrangement between William and Harry, juxtaposed with their mother’s enduring influence and the weight of centuries-old traditions, paints a complex picture of modern royalty. Diana’s warnings about duty, self-sacrifice, and the responsibilities of privilege remain highly relevant as the brothers navigate personal differences, public scrutiny, and institutional expectations.

Patrick Jephson’s insights serve as a poignant reminder that even in the absence of the Princess, her life continues to guide and inspire. By reflecting on her legacy, William and Harry have the opportunity to heal divisions, honor their mother’s memory, and fulfill the obligations of their unique positions in history.

In the end, the hope remains that the lessons left by Diana — the importance of service, humility, and careful attention to family ties — can serve as a roadmap not only for the sons she adored but also for the monarchy as it adapts to a rapidly changing world. Yet, as long as estrangement and mistrust linger, the world watches with bated breath, hoping that Diana’s warnings were not lost to history.