The Princess Royal has taken part in a behind-the-scenes documentary to mark her 70th birthday.

Anne was followed for more than a year by film-makers for the ITV programme, which will feature unseen family footage and conversations with the princess herself, her children, Peter Phillips and Zara Tindall, and her husband, Vice Admiral Sir Timothy Laurence.

The princess will discuss the attempted armed kidnap she endured in 1974, and those closest to her will speak about the highs and lows of her life.

Friends and colleagues of the Queen and the Duke of Edinburgh’s only daughter will also share their thoughts and stories about Anne, with many speaking about her for the first time.

School friends will recall her desire to be one of the girls before she came of age, while her ladies in waiting will admit that they struggle to keep up with her relentless pace.

The documentary will also look the princess’s lifelong juggling of family and duty.

Viewers will see how Anne relaxes with her children, her grandchildren and her animals at her Gloucestershire estate, Gatcombe Park, while husband Sir Tim will reflect on their shared love of the sea and other aspects of their life.

ITV said Oxford Films, whose productions include Our Queen At 90, Diana, Our Mother: Her Life And Legacy, and Queen Of The World, were given unprecedented access to Anne’s public and private life, and the documentary “tells the story of a royal mould-breaker, a princess who refused to follow the script”.

Anne, who is known for her no-fuss approach, turns 70 on August 15.

The hard-working princess, who has devoted herself to public duty, has been described in the past as aiming to serve, but not to please.

She has previously been less than enthusiastic about behind-the-scenes royal documentaries.

In 1969, the BBC’s groundbreaking Royal Family film followed the Windsors for a year and offered the first real look at the private life of the Queen and her children, including Anne.

It was watched by millions of people, and set a precedent in terms of what the public knew about the royals’ private lives.

But Anne later said: “I never liked the idea of the Royal Family film. I always thought it was a rotten idea.

“The attention that had been brought on one ever since one was a child, you just didn’t want any more. The last thing you needed was greater access.”

Oxford Films’ Nicolas Kent, the executive producer of Princess Royal: Anne At 70, said: “It’s been fascinating, especially in such an eventful and significant year, to follow the Princess Royal and hear from her family, friends and colleagues, many of whom are speaking about her for the first time.”

The documentary will be aired ahead of Anne’s birthday, but the final date has yet to be confirmed.