World War II's D-Day: Photos reveal world's largest amphibious invasion

Eighty years ago, D-Day — also known as Operation Neptune — was the largest invasion ever assembled. Some 156,000 Allied troops stormed Normandy, France, by sea and air, to liberate Western Europe from Nazi Germany. The D-Day invasion took place on June 6, 1944, nearly a year before Germany unconditionally surrendered during World War II.

Troops go ashore during training exercises for the Allied D-Day invasion. This photo was captured earlier in 1943. (Keystone/Getty Images) A sign outside Trinity Church, New York City, inviting worshipers to "come in and pray for Allied victory" in the invasion of Normandy on D-Day, June 6, 1944. (FPG/Hulton Archive/Getty Images) Ships and blimps sit off the coast of France on D-Day, June 6, 1944. (The George Stevens Collection at the Library of Congress via AP) Coast Guard LCIs, protected by barrage balloons against low-flying Nazi airplanes, advance upon the beaches of France in the wake of the Stars and Stripes, on D-Day. (PhotoQuest/Getty Images) U.S. servicemen attend a service aboard a landing craft before the D-Day invasion on the coast of France.​​​​​​​ (AP Photo/Pete J. Carroll) General Dwight Eisenhower gives the order of the day, "Full Victory — Nothing Else" to paratroopers in England just before they board planes to participate in the first assault in the invasion of Europe. (U.S. Army Signal Corps Photo via AP) Normandy landings begin as American soldiers leave a barge under fire in World War II, June 6, 1944. (Roger Viollet/Getty Images) Hundreds of American paratroopers drop into Normandy, France, on D-Day. (Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images) A crowd congregates in Times Square on June 6, 1944.   (Anthony Potter Collection/Getty Images) An A-20 Havoc of the 9th US Air Force rears in at a low altitude to blast enemy supply lines on the Cherbourg peninsula, June 1944. (Photo12/UIG/Getty Images) Members of an American landing unit help their comrades ashore during the Normandy invasion.  (Louis Weintraub/Pool Photo via AP) (L-R) Journalists Walter Cronkite, Frank Starr, Melvin K. Whiteleather, Robert Wilson and Alex Paton dash for the phone to transmit their news in Bloomsbury, England on June 6, 1944.   (PhotoQuest/Getty Images) Reinforcements disembark from a landing barge in Normandy during the Allied Invasion of France on D-Day. (Hulton Archive/Getty Images) A group of American assault troops of the 3rd Bat., 16th Inf. Regt., 1st Infantry Div., having gained the comparative safety offered by the chalk cliff at their backs, take a breather before moving inland. Medics who landed with them on D-Day treated them for minor injuries at Collville-Sur-Mer, Normandy. (HUM Images/Universal Images Group via Getty Images) A mortar crew stands back just before firing into a Nazi position somewhere along the Normandy coast of France. (HUM Images/Universal Images Group via Getty Images) A weapon carrier moves through the surf towards Utah Beach, near Cherbourg, from its landing craft off the northern coast of France on June 6, 1944.   (PhotoQuest/Getty Images) Carrying full equipment, American assault troops move onto a beachhead code-named Omaha Beach, on the northern coast of France on June 6, 1944.  (U.S. Army via AP, File) U.S. Army troops crowd into a navy landing craft infantry ship during the D-Day Invasion of Normandy, France on June 6, 1944.   (US Navy/Getty Images) U.S. troops disembark from landing crafts during D-Day on June 6, 1944.  (Imperial War Museum/AFP via Getty Images) The Allied Naval forces engage in the Overlord operation of landing while Allied forces storm Normandy's beaches on D-Day.  (US National Archives/AFP via Getty Images) This article was written by Fox News staff.