LILLE, FRANCE - APRIL 09: Prince William, Duke of Cambridge and Prince Harry walk through a trench during the commemorations for the 100th anniversary of the battle of Vimy Ridge on April 9, 2017 in Lille, France. (Photo by Samir Hussein/WireImage)
LILLE, FRANCE - APRIL 09: Prince William, Duke of Cambridge and Prince Harry walk through a trench during the commemorations for the 100th anniversary of the battle of Vimy Ridge on April 9, 2017 in Lille, France. (Photo by Samir Hussein/WireImage)