Every five years, veterans have made the pilgrimage back to Omaha Beach, Normandy, the site of the D-Day invasion that historians credit with expediting the defeat of Nazi Germany during World War II. As the National World War II Museum put it, "The way to appreciate D-Day’s importance is to contemplate what would have happened if it had failed."

After two years of planning in total secrecy, 150,000 British, Canadian and American soldiers crossed the English Channel during nightfall, arriving on the beaches of German-occupied France at Normandy at 6 a.m. on June 6, 1944. The surprise invasion led to an estimated 10,000 deaths on the Allied side, with nearly 2,000 Allied troops dying on Omaha Beach, the site of the most deadly skirmish of the battle.

In the years since, in addition to the regular commemorations that include staged reenactments and ceremonies led by heads of state of the United States, France, Canada, and the United Kingdom, France also commissioned a sculpture memorial, called Les Brave, to honor the dead. This year’s 75th anniversary memorial is likely to be one of the last with actual veterans of the battle present. Although 35 U.S. D-Day veterans are still expected to travel back to Omaha Beach this month, including medic Ray Lambert, Robert Dalessandro, who organizes the memorials on the American side, said recently to The Atlantic, “In my heart, I know this is the last time we’re going to get D-Day veterans to this ceremony.”

In honor of this year’s commemoration, here is a look back at how the D-Day memorials have evolved over time—and how the battle and the soldiers who fought in it cemented their place in world history.

These Photos Capture the Poignancy of Past D-Day Commemorations
D-Day generals J. Lawton Collins and Henry Cabot Lodge stand over the grave of one of their soldiers on the 10th anniversary of the invasion, 1954. Thomas D. Mcavoy / The LIFE Picture Collection / Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
A small group of veterans return to D-Day to mourn, 1954. Keystone / Stringer via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
Children look on as Allied veterans gather at Omaha Beach for the 20th anniversary of D-Day, 1964. Keystone-France / Gamma-Keystone via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
U.S. president Jimmy Carter and French president Valery Giscard d'Estaing visit Omaha Beach, 1978. Henri Bureau / Sygma / Corbis / VCG via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
U.S. president Ronald Reagan addresses a group of D-Day veterans gathered in Normandy, 1984. Ronald Reagan Library / Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
A D-Day veteran salutes his lost comrades on the 50th anniversary of the battle in 1994. David Turnley / Corbis / VCG via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
Pebbles are arranged to commemorate the invasion on its 50th anniversary, 1994. Wally McNamee / CORBIS / Corbis via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
Hundreds of D-Day veterans and their families watch the D-Day memorial ceremony, 1994. Thierry Orban / Sygma via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
U.S. veteran Ronald MacArthur Hirst and German veteran Franz Gockel relive the invasion from a cliff overlooking the beach, 2004. Xavier Rossi / Gamma-Rapho via Getty Images)
These Photos Capture the Poignancy of Past D-Day Commemorations
War veterans shake hands and exchange memories as they meet again for the 60th anniversary of D-Day, 2004. John van Hasselt / Corbis via Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
British veteran Harry Buckle tears up during the D-Day 65th anniversary, 2009. Mychele Daniau / AFP / Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
A man dressed in World War II attire pretends to be dead during a re-enactment of the bloody events of the invasion, 2009. Joel Saget / AFP / Getty Images
These Photos Capture the Poignancy of Past D-Day Commemorations
Boy Scouts gather together to spell out "Normandy, Land of Liberty," in 2011, two years before the 70th anniversary of D-Day. Stephanie Deve / AFP / GettyImages
These Photos Capture the Poignancy of Past D-Day Commemorations
U.S. veteran Edward W. Oleksak poses in front of the Les Braves sculpture memorial built to commemorate those who died during the invasion, 2014. Joel Saget / AFP / Getty Images