TOPSHOT - Britain's Catherine (L), Duchess of Cambridge, the wife of Britain's Prince William, Duke of Cambridge walk along side King Philippe of Belgium and his wife Queen Mathilde (R) during a ceremony marking the centenary of the battle of Passchendaele, one of the bloodiest of World War I, in Ypres, Western Flanders on July 30, 2017. 
The battle of Passchendaele, also called the third battle of Ypres, took place between July 31 and November 6, 1917 in Passendale, West Flanders. / AFP PHOTO / JOHN THYS        (Photo credit should read JOHN THYS/AFP/Getty Images)