Princess Diana statue unveiled at Kensington Palace by Princes William and Harry

A statue of Diana, Princess of Wales, unveiled by her two sons this afternoon, is based on the final period of her life as she "gained confidence" in her humanitarian role.

A joint statement was issued on behalf of both the Duke of Cambridge and the Duke of Sussex at the short but poignant ceremony in the Sunken Garden at Kensington Palace, the princess's former home, on what would have been her 60th birthday.

The statue was designed to reflect the late Princess’s "warmth, elegance and energy" as well as her work and the impact she had on so many people.

It was based on the final period of her life in her role as an ambassador for humanitarian causes and aims to convey her character and compassion, Kensington Palace said.

The Princess was 36 when she died in a Paris car crash in 1997, five years after she separated from the Prince of Wales and two years after their divorce.

She championed hundreds of causes, but in her final years was particularly well known for her advocacy against landmines.

Shortly before her death she visited Bosnia and Angola, where she was pictured walking through a minefield wearing a visor and bomb-proof breastplate.

Beneath the statue is a plinth engraved with the Princess’s name and the date of the unveiling.

Before it is a paving stone engraved with an extract from the poem, The Measure of A Man, which was printed in the programme of her 2007 memorial service, with the word "man" replaced with "woman".

It reads: "These are the units to measure the worth/ Of this woman as a woman regardless of birth.

"Not what was her station? But had she a heart? How did she play her God-given part?"

Prince William, 39, and Prince Harry, 36, who looked smart in dark suits with ties, arrived a few minutes early for the unveiling and stopped in a shrub-lined path outside the garden to chat to the chairman of the statue committee, Jamie Lowther-Pinkerton.

The royal brothers set the tone for the event as they shared a laugh with their former right-hand man and could be heard chatting animatedly with the ex-Army officer.

The trio spent a few minutes together before Lowther-Pinkerton ushered them down a small flight of steps and into the garden to meet their first guests.

The troubled relationship of the royal brothers has made headlines around the world, but as they entered the Sunken Garden they mirrored each other, walking with their left hands touching their stomachs.

Harry let out a laugh of appreciation when he saw his mother's siblings, as William greeted his aunt Lady Sarah McCorquodale with a kiss on both her cheeks, before warmly greeting his aunt Lady Jane Fellowes and uncle Earl Spencer.

The six-strong "statue committee" headed by Lowther-Pinkerton, the brothers’ former private secretary, were also there, alongside sculptor Ian Rank-Broadley and garden designer Pip Morrison.

Harry clapped his hands as if in anticipation when he reached Mr Rank-Broadley and glanced over at the statue covered in a large green cloth.

Mr Morrison was stood nearby and could be overheard telling the royal brothers: "It's a collaborative effort."

When the two dukes got into place either side of the statue, William said "ready?" before they pulled off the cloth and the guests applauded.

The statue was commissioned by the two brothers in 2017 to memorialise their mother and mark the twentieth anniversary of her death.

They wanted the statue to recognise her positive impact both in the UK and around the world, and to help future generations understand the significance of her place in history.

The Princes hope that the statue will help visitors to Kensington Palace to reflect on their mother’s life and legacy.

The brothers have been intimately involved in every aspect of its design, liaising with the committee throughout to ensure the "beautiful" and "informal" memorial reflects the late Princess’s youthful and playful nature.

'Absolutely charming and a fitting tribute'

"It is not in any way austere or imperious," said a source close to the project. "Both brothers wanted to ensure that the artwork is something that really resonates with the public.

"It’s absolutely charming and such a fitting tribute."

All eyes were on the body language between the warring brothers, both of whom were said to be determined to put their differences aside and to remain "professional".

The pair have barely spoken since the Sussexes moved to California, with the rift only deepening in recent months as Prince Harry made a raft of accusations about his family in various interviews.

Before he relocated, the brothers are said to have spent "weeks" deciding where exactly the statue should be located in the grounds of the royal residence in west London, which will always be synonymous with the Princess.

Work on the garden began in October 2019, and since then five gardeners, led by Graham Dillamore, deputy head of gardens and estates at Historic Royal Palaces, have spent a total of 1,000 man hours working on planting.

The garden includes more than 200 roses, 500 lavender plants, 300 tulips, 100 dahlias and 100 forget-me-nots.

In total, 50 different varieties have been planted, including wisteria, agapanthus, clematis, hydrangeas, hostas, violas and petunias.

The brothers appeared interested in the changes to the garden, pointing to the beds filled with a range of flowers and plants, some of which were favoured by their late mother.

From tomorrow, the public will have unrestricted access to the statue in the Sunken Garden, which is open throughout the day.

But all concerned are determined that it will not become a place of pilgrimage, lost in a sea of flowers.

"Any flowers or tributes left there will be removed and placed at the golden gates, where they have always been permitted," a source said.

"There is a strong desire that this does not become a shrine."