VIMY, FRANCE - APRIL 09:  The Prince of Wales, The Duke of Cambridge, Prince Harry,  Canadian Prime Minister Justin Trudeau, French President, Francois Hollande  and Governor General of Canada,  David Johnston attend the centenary commemorative service at the Canadian National Vimy Memorial on April 9, 2017 in Vimy, France. The Battle Of Vimy Ridge was fought during WW1 as part of the initial phase of the Battle of Arras. Although British-led it was mostly fought by the Canadian Corps. (Photo by Pierre Suu/Getty Images)