LONDON, ENGLAND - APRIL 05:  The Very Reverend Dr John Hall, Dean of Westminster receives Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry as they arrive for the Service of Hope at Westminster Abbey on April 5,2017 in London, United Kingdom. The multi-faith Service of Hope was held for the four people killed when Khalid Masood committed an act of terror in Westminster on Wednesday March 22. Survivors, bereaved families and members of the emergency services joined The Duke and Duchess of Cambridge, Prince Harry, the Home Secretary, Amber Rudd and London Mayor, Sadiq Khan, in the congregation.  (Photo by Dan Kitwood/Getty Images)