Britain's Prince William, Duke of Cambridge, (L), his wife Britain's Catherine, Duchess of Cambridge (2L) and Britain's Prince Harry (R) are greeted as they arrive for a visit to County Hall and The London Eye in central London on October 10, 2016.
The Duke and Duchess of Cambridge, along with Prince Harry, were due to speak at an event recognising World Mental Health day. / AFP / Daniel Leal-Olivas        (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)