Open this photo in gallery: The remains of the Mulberry Harbour in Arromanches, Normandy region, France, on April 12.Christian Hartmann/Reuters Veterans and world leaders will meet in Normandy, northwestern France, on June 6 to mark the 80th anniversary of the 1944 D-Day landings, when more than 150,000 Allied soldiers invaded France to drive out the forces of Nazi Germany. Eighty years later, Normandy’s beaches and fields still bear the scars of the fighting that erupted on D-Day, history’s largest amphibious invasion. Here is what you need to know about the event: Why does the ceremony matter? With war raging on...