D-Day invasion: What is D-Day and what happened on June 6, 1944?

It was 74 years ago, on June 6, 1944, that the invasion of Europe began behind the largest landing force the world had ever seen.

The invasion, which became known as D-Day, began as Operation Neptune, part of Operation Overlord which was the code name for the Allied invasion of northwest Europe. U.S. Gen. Dwight David Eisenhower was the Supreme Commander of the Allied Forces in Europe. Eisenhower planned and directed the invasion, and on the night before the operation told troops that their mission would not be an easy one," but that he had "full confidence" in the men's "courage and devotion to duty and skill in battle."

So what happened on that day? Here’s a look:

The operation began at 12:15 a.m. on June 6, 1944, when more than 13,000 Americans from the 82nd and 101st Airborne divisions began to parachute behind German lines. About three hours later, Allied bombers struck the German lines near the 50-mile strip along the Normandy coasts. According to historians, 7 million pounds of bombs would by dropped by the end of the day.

Two hours later, at 5 a.m., seven battleships, 18 cruisers, and 43 destroyers began the naval bombardment of the coast. The bombardment lasted nearly an hour and a half, leading up to the troop landings which began at 6:31 a.m.

Allied Troops headed ashore on 50 miles of coastline that had been divided into five landing zones – Utah, Omaha, Gold, Juno, and Sword. U.S. troops took Utah and Omaha, Canadians landed at Juno and British troops took Gold and Sword.

How many people took part in the D-Day invasion?

There were 160,000 Allied troops – of that number, 73,000 were Americans. 

What was the toll?
It’s estimated that 4,500 Allied forces died in the invasion. More than 2,000 Americans were killed at Omaha Beach, alone.

The numbers

• 1,600 aircraft flew cover as troops landed on the beaches.
• 14,674 sorties were flown on June 6, 1944.
• 127 Allied planes were shot down or crashed.
• 1,213 naval combat ships, 4,126 landing ships and landing craft, 736 ancillary craft and 864 merchant vessels took part in the invasion.
• 50,000 German troops were spread out along the landing area.
• 172.5 acres in the Normandy American Cemetery is one of 14 permanent American World War II military cemeteries on foreign soil. 
• 10,000 Allied troops were expected to be killed on that day; less than half of that number were killed in the invasion.

RELATED: Photos of D-Day Invasion then and now

Remembering the sacrifice

On the 40th anniversary of the invasion, President Ronald Reagan delivered one of the most moving speeches ever given at a D-Day memorial ceremony. Here is that speech:

Sources: D-Day Museum; Encyclopedia Britannica; The Associated Press; The Ronald Reagan Presidential Library; History.com 

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