It's not every day you expect to run in to a member of the royal family, so there's no doubt that Prince William left royal well-wishers completely shocked when he surprised them last night.
Many fans of the family had been gathered outside London's Kensington Palace - where William and his family live - since 5.30am yesterday morning, to hold a vigil to Princess Diana.
Yesterday would have been her 58th birthday, so many of her dedicated fans came, as they do every year, to pay tribute to the late Princess.
But this year, those fans were left thrilled when Prince William quietly left his home, Apartment 1A, and walked up to greet and thank the waiting crowd for their sweet gesture for his mother.
One man, John Loughrey, 59, revealed that the visit from royalty made him 'very emotional'. He told the Daily Mail, "William told me he knew we'd been coming here for years and thanked us for what we were doing for his mother. I'm still shaking now. I feel very emotional.
"He said 'I'm touched by what you do, you've got quite the collection.' I told him that I pray for his mother every Sunday at Westminster Abbey and he seemed really touched."
MORE:Meghan’s new eternity ring from Prince Harry includes the sweetest tribute to their new family
John and plenty of other fans leave pictures, bunting, flowers and candles at Kensington Palace, Diana's final home, each year on both the anniversary of her death and her birthday.
Prince William and his young brother Harry also went to see the touching tributes back in 2017, on the 20th anniversary of their mother's death.
The Daily Mail reports that yesterday, the Duke of Cambridge stayed chatting with fans for around seven minutes, before a larger crowd began to gather and he was taken back inside by his security detail.
That same day, his wife the Duchess of Cambridge was busy on an official engagement, having invited a group of young people from four different charities she supports to her RHS 'Back to Nature' garden.
The garden, which Catherine designed and created herself, has just re-opened at Royal Hampton Court Palace Garden Festival, after being shown at the Chelsea Flower Show originally.
