Prince William surprises fans keeping vigil to mark Princess Diana's birthday

Prince William has surprised a small group of royalists keeping vigil at Kensington Palace to mark what would have been Princess Diana's 58th birthday.

The Duke of Cambridge saw the gathering on Monday and decided to say hello.

Dressed casually in a check collared shirt and navy trousers, he arrived with just a small security detail and spent about seven minutes speaking with the crowd, reports the Daily Mail.

The group of six was armed with photos, badges and bunting celebrating the Princess of Wales. They had been at the Kensington Palace gates all day when they were met by William, who showed up just before 7pm.

The Duke thanked the fans and shook their hands, showing his appreciation for the vigil.

'He said 'I'm touched by what you do, you've got quite the collection'," John Loughrey, 59, said.

"I told him that I pray for his mother every Sunday at Westminster Abbey and he seemed really touched.

"He shook my hand three times, he has a really firm shake, and I felt a beautiful feeling go through my body. I think I'm still shaking now. I feel very emotional."

Princess Diana was born on July 1 and her birthday has become a time of reflection for her many fans around the world.

A statue of the former Princess of Wales is due to be erected within the grounds of her former home, Kensington Palace, with William telling the group "we just want to make sure it is right".

Diana's legacy remains as strong as ever, 22 years after her death in a car crash while on holiday in Paris.