LONDON, UNITED KINGDOM - APRIL 23: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Prince Harry, Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge attend the start of the 2017 Virgin Money London Marathon on April 23, 2017 in London, England. The Heads Together mental heath campaign, spearheaded by The Duke & Duchess of Cambridge and Prince Harry, is the marathon's 2017 Charity of the Year. (Photo by Max Mumby/Indigo/Getty Images)