French President Francois Hollande (4th L), Canadian Prime Minister Justin Trudeau (3rd L), his wife Sophie Gregoire (L) and son Xavier (2ndL), Britain's Charles, Prince of Wales (4th R), Governor General of Canada David Johnston (C), his wife Sharon (3rd R) Britain's Prince William (2nd R), Duke of Cambridge and Britain's Prince Harry (R) pose at the Canadian National Vimy Memorial during a commemoration ceremony to mark the 100th anniversary of the Battle of Vimy Ridge, in Vimy, near Arras, northern France, on April 9, 2017. REUTERS/Philippe Huguen/POOL