HistoryExtra Academy D-Day and the Normandy Campaign course

HistoryExtra Academy D-Day and the Normandy Campaign quiz: week four. This is a premium piece of content available to subscribed users.

HistoryExtra Academy video lecture: launching Operation Overlord. This is a premium piece of content available to subscribed users.

HistoryExtra Academy D-Day and the Normandy Campaign quiz: week three. This is a premium piece of content available to subscribed users.

HistoryExtra Academy video lecture: Deceiving the Nazis. This is a premium piece of content available to subscribed users.

A Landing Craft, Vehicle, Personnel (LCVP) approaches Omaha Beach, Normandy on D-Day (Photo by Galerie Bilderwelt/Getty Images)

"Hitler slept through D-Day", plus four other facts about the Normandy Landings you might not know.... This is a premium piece of content available to subscribed users.

HistoryExtra Academy D-Day and the Normandy Campaign quiz: week two. This is a premium piece of content available to subscribed users.

HistoryExtra Academy video lecture: Planning for D-Day. This is a premium piece of content available to subscribed users.

HistoryExtra Academy video lecture: D-Day – the decision to invade. This is a premium piece of content available to subscribed users.

HistoryExtra Academy D-Day and the Normandy Campaign quiz: week one. This is a premium piece of content available to subscribed users.

The neutral USA entered World War II only when a Japanese fleet launched a big surprise air raid against its Pacific naval base at Pearl Harbor in Hawaii on 7 December 1941. (Photo by Fox Photos/Getty Images)

Second World War

When and why did the US get involved in WW2?

Allied troops hide from enemy shelling during the battle of Caen. The town was finally captured after several weeks of intensive fighting. The white markings on their shoulders were later added to the photograph by a censor to hide the name of the battalion. (Photo by Hulton-Deutsch/Hulton-Deutsch Collection/Corbis via Getty Images)

The battle for Normandy: what happened after D-Day?. This is a premium piece of content available to subscribed users.

US President Franklin Delano Roosevelt and British prime minister Sir Winston Churchill, meeting during the Casablanca conference in 1943. (Photo by AFP/Getty Images)

Second World War

Churchill and D-Day: did the prime minister oppose the Normandy landings?

Historian Peter Caddick-Adams

Exclusive podcastPeter Caddick Adams on whether D-Day could have failed. This is a premium piece of content available to subscribed users.

American soldiers head towards the French coast, June 1944. (Photo by Getty Images)

D-Day: everything you wanted to know. This is a premium piece of content available to subscribed users.

Troops from the 48th Royal Marines at Saint-Aubin-sur-Mer on Juno Beach, Normandy, France, during the D-Day landings, 6 June 1944. (Photo by Hulton Archive/Getty Images)

Second World War

Your guide to D-Day: what happened, how many casualties were there, and what did it accomplish?

To the point: soldiers prepare themselves for hand-to-hand combat by learning bayonet skills. (Photo by Fox Photos/Getty Images)

The road to D-Day: the masterplan. This is a premium piece of content available to subscribed users.

Members of a British parachute regiment consult their maps during a training exercise just weeks before D-Day. Training was intensive – and dangerous. (Photo by Haywood Magee/Picture Post /Hulton Archive/Getty Images)

The road to D-Day: getting ready for action. This is a premium piece of content available to subscribed users.

Allied troops on the landing crafts did not know if they would survive D-Day, but they knew the beaches had to be taken. (Photo by: Universal History Archive/UIG via Getty Images)

D-Day: the WW2 battle through the eyes of the men who were there. This is a premium piece of content available to subscribed users.

The killing zone: This photograph by Robert F Sargent, known as ‘Taxis to Hell – and Back – into the Jaws of Death’, shows American troops wading towards Omaha Beach on the morning of 6 June 1944. (Photo via Smith Collection/Gado/Getty Images)

D-Day: 24 hours that changed the world. This is a premium piece of content available to subscribed users.

Troops of the 9th Canadian Infantry Brigade (Stormont, Dundas, and Glengarry Highlanders) going ashore, Normandy, France, 6 June 1944. (Credit: Gilbert Alexander Milne/Canada. Dept. of National Defence/Library and Archives Canada/PA-122765)

Second World War

“Free people everywhere should remember them”: the Canadians’ role in D-Day

Holding court: Bernard Montgomery briefs reporters on progress in France, 1944. (Photo by Cynthia Johnson/The LIFE Images Collection/Getty Images)

In defence of Monty: James Holland on the Allied commander's D-Day decisions. This is a premium piece of content available to subscribed users.

British troops learn to swim in full kit on a training course in May 1944. "A blind man could see something big was about to happen," said one soldier. (Image by Getty Images)

D-Day: why the training was deadlier than the assault. This is a premium piece of content available to subscribed users.

American Flying Fortress bombers and a Mustang fighter practise formation flying over England, training for rain that would help break Nazi resistance. (Photo by PhotoQuest/Getty Images)

The LibraryThe Allies’ big idea: the largest air battle of the Second World War. This is a premium piece of content available to subscribed users.

Winston Churchill, Josef Stalin and Franklin Roosevelt exchanged almost 700 messages during the Second World War. (Illustration by Hugh Cowling for BBC History Magazine)

Churchill, Stalin and Roosevelt: the big three’s war of words. This is a premium piece of content available to subscribed users.

Operation Barbarossa, which began on 22 June 1941, saw more than three million German troops surge into the Soviet Union along a front of more than 1,000 miles. (Photo by Art Media/Print Collector/Getty Images)

Barbarossa and Britain. This is a premium piece of content available to subscribed users.