The Duke and Duchess of Cambridge visited the Royal Marsden Hospital in Sutton, England almost 30 years after Princess Diana's visit, to the mark the opening of a new cancer treatment ward for children.

The Royal Couple arrived at the hospital to a grand welcome with cheers and union flags as they prepared to open the £18million Oak Centre for Children and Young People. It were their first public appearance together in weeks as Middleton has been deciding which charities she would work on behalf of.

The Duchess, who was wearing a cream Amanda Wakeley dress and LK Bennett shoes spoke with patients in the ward and shared a joke with leukemia sufferer Digby Davisdon, who was back in the hospital following a relapse, the Daily Mail reported.

The couple also met with nine-year-old Fabian Bate who was in the middle of a four-hour chemotherapy treatment session for his acute lymphoblastic leukemia. Bate hailed the duchess for her kindness after the told him she would post a personal message on his family blog, The Press Association reported.

The Duchess told Bate's family how sorry she was the treatment had not worked the first time, after asking many questions about his illness.

When we told her about the blog she said 'I'll look that up and post a message.' She sounded like she really meant it so we'll see, Bate's mother told The Press Association.

In May 2007, Prince William became President of the Royal Marsden Hospital, a position previously held by Diana, Princess of Wales. The Prince has visited the hospital a number of times, and in December 2005, undertook two days of work experience there. Prince William helped out in a variety of departments, including medical research, catering, and fundraising, as well as visiting a number of wards, including the Children's Unit.

The Royal Marsden does an extraordinary job in treating thousands of cancer patients every year, William said during his inauguration as President of the hospital. The standards of care and compassion of its staff are unsurpassed in the world. I am, therefore, delighted and honored to become President of the Royal Marsden and will do whatever I can to support its innovative and vital work.

Tessa Green, Chairman of The Royal Marsden NHS Foundation Trust said, William follows in the footsteps of his mother, Diana, Princess of Wales, who became our president in 1989. The Prince has spent many hours with us at the hospital and it is wonderful that he is so committed to helping our fight against cancer.

Founded in 1851, the Royal Marsden was the first hospital in the world dedicated to cancer treatment and research into the causes of cancer.

Today the hospital, with its academic partner, The Institute of Cancer Research, forms the largest comprehensive cancer center in Europe with over 40,000 patients from the UK and abroad seen each year.