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