Prince Harry concluded his U.K. trip with a visit to a charity honoring his later mother, Princess Diana, after his surprising reunion with King Charles III. Harry, 40, attended an event for The Diana Award, the only charity established in Diana's name after her death, in London on Thursday, September 11. He joined a group of people who discussed how their social action initiatives have helped uplift mental health. While speaking to the crowd, Harry paid tribute to his mom. "My mother believed in the power and agency of young people to positively impact the world.