As he approached his 18th birthday in September 2002, Prince Harry made a highly publicized visit to Great Ormond Street Hospital in London intended to counter his emerging "party prince" image and to signal a commitment to continuing the charitable work of his late mother, Princess Diana, royal correspondent Katie Nicholl wrote in her book William and Harry.

Nicholl, who witnessed Harry’s social life while working as a showbiz reporter, recalled scenes of the young prince at nightclubs but said the hospital visit showed a different side. She wrote that Harry spent the days leading up to his birthday meeting sick children at Great Ormond Street to demonstrate there was "far more to him than just partying." The contrast is striking against recent measures of his public standing: a YouGov opinion poll published this year put his popularity at 33 percent.

Hospital staff described a warm encounter. Nicholl said Harry was tactile and down‑to‑earth, able to make seriously ill children laugh, and at ease speaking to photographers while ensuring the importance of the visit was conveyed. The prince toured the hospital’s oncology ward and the renal unit, the latter having been opened by Diana on her final official visit in February 1997. Great Ormond Street’s oncology ward was housed in the New Variety Club Building, opened by Diana in 1993.

Jane Collins, then chief executive of the hospital, briefed Harry in the chapel where a bust of his mother stood. Collins told him that flowers were placed at the bust on the anniversary of Diana’s death and presented him with a framed collage containing a photograph of Diana with a young patient and plaques commemorating parts of the hospital she had helped fund. Harry later said he wanted "to carry on the things she didn't quite finish." He had previously been treated at Great Ormond Street at age three for a hernia.

Contemporaneous reports said the prince found the visit emotionally challenging but inspiring. He told reporters he was struck by how cheerful children could be despite gruelling treatments, noting the difficulty of hours spent on dialysis and expressing admiration for patients and families.

A time capsule buried by Diana to mark the laying of the foundation stone of the Variety Club Building was opened in August to make way for a new children's cancer centre. The capsule contained objects chosen in a 1990s Blue Peter competition intended to represent life at the time, including a Kylie Minogue CD, a solar‑powered calculator, a passport, a pocket television and a hologram.

Observers and associates have linked Harry’s early charitable engagements to Diana’s broader approach to public service. Vivienne Parry, a friend of the late princess, told Nicholl that Diana tackled difficult issues such as AIDS and landmines and did not confine herself to what Parry called "the fluffy stuff," a tendency she said Harry and his elder brother, Prince William, have shown in their own charitable choices.

Harry co‑founded Sentebale in 2006 to support children and young people affected by HIV and AIDS in Southern Africa, invoking his mother’s example when discussing the charity’s mission. In a 2009 speech marking Sentebale’s third anniversary, Harry said he and co‑founder Prince Seeiso had established the charity "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."

Sentebale later experienced a public dispute among trustees that led to Harry and Prince Seeiso stepping back from the charity’s governance. A subsequent Charity Commission inquiry found no evidence to substantiate allegations of bullying or harassment but said the internal disagreement had "severely impacted the charity's reputation." The dispute has been cited in media coverage of Harry’s charitable record alongside his earlier, hands‑on hospital work.

Harry returned to Great Ormond Street in 2017 for a private visit with a terminally ill boy he had previously met. As the Duke of Sussex approaches his 41st birthday this month, the hospital visit he made as a teenager remains a frequent reference point in accounts of how his public role evolved — from youthful notoriety toward a focus on health and humanitarian work connected to his mother’s legacy.