YPRES, BELGIUM - JULY 31: (R-L) Prince Charles, Prince of Wales, King Philippe of Belgium,  Prince William, Duke of Cambridge, Queen Mathilde of Belgium, Catherine, Duchess fo Cambridge and Vice Admiral Sir Tim Laurence arrive at a ceremony at the Commonwealth War Graves Commisions's Tyne Cot Cemetery on July 31, 2017 in Ypres, Belgium.  The commemorations mark the centenary of Passchendaele - The Third Battle of Ypres.  (Photo by Darren Staples - Pool/Getty Images)