Prince Harry, who celebrates his 41st birthday next week, was once known as the ‘party prince’, a nickname he gained after one too many Boujis nights out in his teens.

But back in September 2002, Harry’s 18th birthday was on the horizon, and he was keen to shake off his Playboy image in the media.

Royal correspondent Katie Nicholl witnessed Harry’s partying first-hand while working as a showbiz reporter for the Mail on Sunday.

‘He was clearly very sociable, and as he sipped his vodka and cranberry, it was obvious that he was relaxed and self-assured among girls,’ Nicholl wrote in her book, William and Harry.

‘He had recently been voted Britain’s most eligible bachelor by society magazine Harper’s Bazaar, which cemented his standing among the social elite, not that he needed a poll to prove he was popular.’

This comes in stark contrast to today; in the latest YouGov opinion poll his popularity sat at just 33 per cent.

Nicholl continued: ‘Harry uses his first official press interview to argue that his critics were wrong. He was not, he insisted, a party animal.

‘He had seen his Uncle Andrew labelled a Playboy and his Aunt Margaret a bon vivant in her heyday, and he was determined not to be stereotyped as the royal rebel.

Back in September 2002, Prince Harry's 18th birthday was on the horizon and he was keen to shake off his Playboy image in the media

Harry, pictured with Princess Diana, hoped to continue the legacy of his mother's charity work

The cover of Nicholl's book, William and Harry, is picturedRoyal correspondent Katie Nicholl - pictured - witnessed Harry's partying first-hand while working as a showbiz reporter for the Mail on Sunday

‘There was far more to him than just partying, and to prove his point, he spent the days leading up to his birthday visiting sick children at Great Ormond Street Hospital in London.

‘While it may have been a carefully orchestrated PR exercise, there was no mistaking Harry’s ease in the role.

‘He was tactile and down-to-earth and able to make the sickest children laugh.

‘While William tended to be nervous in front of the cameras, Harry managed to joke with the photographers while making sure the importance of the visit was relayed.

‘He hoped to continue the legacy of his mother’s charity work.’

Princess Diana became the President of Great Ormond Street in 1989 and regularly visited the specialist children’s hospital.

‘I want to carry on the things she didn’t quite finish,’ he said.

The Daily Mail reported at the time that meeting patients of Giraffe Ward was an experience the prince was later to recall with admiration, saying he had marvelled at how cheerful the children had been in spite of their situation.

Pictured: Harry meets 11-year-old leukaemia patient, Samantha Ledster, in the Oncology Department during a visit to Great Ormond Street Hospital on September 12, 2002

The Daily Mail reported at the time that meeting patients of Giraffe Ward was an experience the prince was later to recall with admiration, saying he had marvelled at how cheerful the children had been in spite of their situation

During his visit, Harry also toured the hospital's renal unit opened by his mother on her final official visit on Valentine's Day 1997. Pictured: Harry meets kidney dialysis patient, Michael Anderton

Great Ormond Street’s oncology ward, for children seriously ill with leukaemia, is housed in the New Variety Club Building at the time, which was opened by Diana in 1993.

During his visit, Harry also toured the hospital’s renal unit opened by his mother on her final official visit on Valentine’s Day 1997.

Harry, who was once treated at the hospital when he had a hernia operation at the age of three after complaining of stomach pains, began his visit at Great Ormond Street by receiving a private briefing in the chapel, where a bust of his late mother is on display.

Later, hospital chief executive Jane Collins showed the prince an area near the entrance and told him: ‘On the anniversary of your mother’s death, we put flowers there. She was a great friend to us.’

She presented Harry with a framed collage containing a picture of Diana holding a young patient and copies of two plaques commemorating parts of the hospital she had raised money to build.

Harry later said he had enjoyed his visit.

‘It was the hardest to take, with all the kids having their treatments, but seeing them so cheerful was something I had not expected. It can’t be easy spending so many hours on a dialysis machine, and you could not fail to have so much admiration for them,’ he said.

A time capsule buried by the late Princess was opened last month, revealing a Kylie Minogue CD, a solar-powered calculator and a passport.

Harry looks at a photo taken by dialysis patient, Fred Ayisi, during a visit to Great Ormond Street Hospital
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Harry looks at a photo taken by dialysis patient, Fred Ayisi, during a visit to Great Ormond Street Hospital

Hospital chief executive Jane Collins presented Harry with a framed collage containing a picture of Diana holding a young patient
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Hospital chief executive Jane Collins presented Harry with a framed collage containing a picture of Diana holding a young patient

Princess Diana became the President of Great Ormond Street in 1989 and regularly visited the specialist children's hospital
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Princess Diana became the President of Great Ormond Street in 1989 and regularly visited the specialist children’s hospital

The box was sealed to mark the laying of the foundation stone of the hospital’s Variety Club Building, which opened in 1994.

The items in the capsule were selected by two children who won a Blue Peter competition and were intended to represent life in the 1990s.

Other objects included a pocket TV, a snowflake hologram and a photo of Princess Diana.

The time capsule was meant to be unearthed in ‘hundreds of years’ but was dug up to make way for the construction of a children’s cancer centre.

Both William and Harry have spoken about the impact of losing their mother at such a young age, with Harry describing the feeling as a ‘gaping hole that could never be filled’.

Nicholl quoted Diana’s friend Vivienne Parry as saying: ‘Diana was involved with Aids charities and landmines – she didn’t want to do the fluffy stuff – and I think William and Harry are very like her in that respect.

‘She overcame all sorts of social barriers, and Harry and William are doing the same.

‘Like her, they also identify with people on the margin. They want to do the difficult work.

Diana visits patients at Great Ormond Street in March 1991 wearing a suit by Chanel
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Diana visits patients at Great Ormond Street in March 1991 wearing a suit by Chanel

Diana is pictured meeting David Meaney and his mother Monica outside Great Ormond Street hospital where the princess laid a foundation stone and time capsule to mark the start of a major redevelopment scheme
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Diana is pictured meeting David Meaney and his mother Monica outside Great Ormond Street hospital where the princess laid a foundation stone and time capsule to mark the start of a major redevelopment scheme

Nicholl quoted Diana's friend Vivienne Parry as saying: 'Diana was involved with Aids charities and landmines - she didn't want to do the fluffy stuff - and I think William and Harry are very like her in that respect'
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Nicholl quoted Diana’s friend Vivienne Parry as saying: ‘Diana was involved with Aids charities and landmines – she didn’t want to do the fluffy stuff – and I think William and Harry are very like her in that respect’

‘We all remember Diana holding an Aids patient in her arms at a time when people thought you could get the disease through touching.

‘The boys’ trajectory is very similar, and Harry has his mother’s gift – we’ve seen it with him in Africa.’

Harry co-founded the charity Sentebale in 2006 to support young people affected by HIV and AIDS in Southern Africa, honouring his mother’s memory.

Nicholl wrote: ‘Although William loves Africa, in terms of charitable work this is very much Harry’s domain, and in March 2009 he made his most political public speech to date on Sentebale’s third anniversary.

‘”Prince Seeiso and I founded Sentebale in memory of our mothers. They worked tirelessly to help the deprived and the afflicted and – in our way – we aspire to follow their great example.”‘

However, the charity experienced a public ‘breakdown of relationships’ after a dispute between the board chair and other trustees, leading to Harry and co-founder Prince Seeiso stepping down.

A Charity Commission investigation found no evidence to support allegations of bullying or harassment but noted the internal dispute had ‘severely impacted the charity’s reputation’.

The Princess of Wales talks with AIDS patient Wayne Taylor at the Casey House AIDS hospice in Toronto in 1991
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The Princess of Wales talks with AIDS patient Wayne Taylor at the Casey House AIDS hospice in Toronto in 1991

Harry co-founded the charity Sentebale in 2006 to support young people affected by HIV and AIDS in Southern Africa, honouring his mother's memory
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Harry co-founded the charity Sentebale in 2006 to support young people affected by HIV and AIDS in Southern Africa, honouring his mother’s memory

Sentebale experienced a public 'breakdown of relationships' after a dispute between the board chair and other trustees, leading to Harry and co-founder Prince Seeiso stepping down
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Sentebale experienced a public ‘breakdown of relationships’ after a dispute between the board chair and other trustees, leading to Harry and co-founder Prince Seeiso stepping down

As Harry celebrates his birthday this year, he will likely be reminded of the work of his mother, who died just weeks before he turned 13.

The Duke returned to Great Ormond Street in 2017 for a private with Ollie Carroll, a terminally ill boy with Batten disease whom he had previously met at the WellChild awards, where he is a patron.

While recent headlines surrounding Sentebale cast a dark shadow over Harry’s charity work, his time spent with children at Great Ormond Street on his 18th birthday not only helped heal his fractured reputation but also continued the work his mother set out to achieve.