Canadian Prime Minister Justin Trudeau (3rd L), his wife his wife Sophie Gregoire (L) and son Xavier (2nd L), (From 4th L) French President Francois Hollande (4th L), Governor General of Canada David Johnston (5th L), his wife Sharon (3rd R), Britain's Charles, Prince of Wales (4th R), Britain's Prince William, Duke of Cambridge (2nd R), and Britain's Prince Harry (R) pose as they visit the Canadian National Vimy Memorial in Vimy, near Arras, northern France, on April 9, 2017, during a commemoration ceremony to mark the 100th anniversary of the Battle of Vimy Ridge, a World War I battle which was a costly victory for Canada, but one that helped shape the former British colony's national identity. / AFP PHOTO / POOL / Philippe HUGUEN        (Photo credit should read PHILIPPE HUGUEN/AFP/Getty Images)