'Andrew scandal has rocked the monarchy - Kate and William need to prepare'

The royal family is one of the most scrutinised and talked about institutions in the world, and yet throughout history, it is not often that we learn who they really are.

As figureheards of an establishment which has in recent years undergone massive change - through internal friction, damaging scandal and personal heartache - it is worth considering the effect on those at the very centre of such seismic events and how their experiences shape their public roles. The Prince and Princess of Wales, who consistently rank as the two most popular members of the monarchy, stand on the precipice of a new era.

In producing this biography, through months of extensive research and almost one hundred interviews with those closest to them throughout the key moments in their lives, I have sought to provide the definitive account of who they are and the reasons behind shaping their vision of the monarchy in the modern age. But what does this mean, and what do they stand for?

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The privilege afforded to the prince and princess, in a time when many are struggling with the pressures of daily life can not be ignored. Yet, despite their obvious advantages, they are, of course, people too. Individuals with their own lives, goals, feelings and struggles, all of which determine their character. How they deal with all of this matters, not just at home, but the world over.

Even for those who question the suitability of the institution, they too must surely show some investment as to whether those people serve the public with their actions.

In nearly a decade of covering royal engagements both at home and around the world, I have reported on the biggest stories to have followed the royal family in a truly unprecedented era.

not only delves into the unseen and private moments that have had the greatest impact, but offers never-before-told context on the issues the Prince and Princess of Wales have weathered together, as they set out to secure the monarchy’s safe continuation at a time of extreme change and turmoil.

Our future king and queen face a huge task of not only ensuring the monarchy's survival, but making sure it thrives and can be relevant in the modern world.

The death of the late Queen Elizabeth IIbrought to a close a reign spanning 70 years, and arguably the end of a time where reverence was almost universally guaranteed.

King Charles’s accession has coincided with a period of extreme change and turmoil, where the painful memories left by the Duke and Duchess of Sussex’sdeparture from royal life and the devastating scandal involving the former Prince Andrew continue to leave a stain on the institution.

While they may be in a minority, events in recent days have shown us that both the public and political classes both here and in the United States in regards to the allegations surrounding the King's brother Andrew, questions are being raised on whether the monarchy is on the right side of history.

As central figures, the Prince and Princess have already begun shaping the future of the institution, although up until now their influence has had to fall in line with the desires and ambitions of the late Queen and now King Charles.

But I have always believed that there is so much to William and Catherine that the spectacle reveals - and it has not been without conflict. Prince William has spoken publicly of his desire for change and evolution, but again, what does this look like and how achievable is it?

From those at the centre of the couple’s lives, from private secretaries to senior aides, close friends and former associates, what appears is a truly unique portrait of the next generation that is breaking the mold.

The King himself is acutely aware of the parameters of taking on the ‘top job’ in his mid 70s, and while he has been typically in fine health, a cancer diagnosis has certainly put into focus how much his son and heir - and his daughter-in-law - need to be prepared for the next stage in their lives.

Having been granted unique and exclusive access to William and Catherine’s most trusted circle, what has emerged is how they have united in times of chaos and upheaval to form a formidable partnership that will shape the monarchy for generations to come.

At the centre is a very human, emotional story, which moves beyond the headlines as it explores love, resilience, and their journey together as they navigate their public duties amid this unprecedented era.

William and Catherine: The Intimate Inside Story, published on 26 February by Ebury, Penguin Random House, is available to pre-order now.