Prince William wraps his arm around a young cancer patient after arriving at the Royal Marsden Hospital with his bride.
Looking on, during what was only her second UK charity engagement since their wedding, the Duchess smiles at the touching scene.
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She was there to support her husband as he returned to the Royal Marsden to open a new cancer treatment ward for children.
The Sutton hospital holds a special place in William's heart and it was an engagement he was determined not to miss.
At 10am on Thursday, he finished a packed 24 hour shift with the RAF's search and rescue team.
With no time to sleep, he jumped in a helicopter to meet up with his wife in London before heading straight to the hospital.
He became president of the Royal Marsden in May 2007 – a role held by his mother Diana for several years before her death.
William and Kate – elegant in an Amanda Wakeley dress and her favourite nude L.K Bennett heels – chatted with patients and staff as they toured the £18 million Oak Centre unit, which is funded entirely from charitable donations.
The 29-year-old prince was then invited to unveil a plaque to officially open the centre.
William's late mother Diana was a huge supporter of the hospital; she auctioned off 79 dresses – at son's suggestion – helping raise funds for the Marsden weeks before her passing in 1997.
And a decade later, the hospital was one of the charities to benefit from Concert for Diana, a celebratory event staged by her boys.
In 2008, royal help was needed once again when a fire broke out in one of the wings, leading to the evacuation of those being treated.
William came in person to thank firefighters and lift spirits among nurses and patients, following this up with another visit to check on repair work.
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