Throughout WWII, Germany and its allies encrypted messages using Enigma machines. The Germans considered the Enigma code to be unbreakable, but the codebreakers at Bletchley Park in Buckinghamshire, the British forces' intelligence centre, managed to decipher the code. This enabled the British to plan operations to defeat the Germans. (Photo by SSPL/Getty Images)

This shows codebreakers in the registration room in hut 6 at Bletchley Park. (Photo by SSPL/Getty Images)

The code breakers were helped by the first ever computer to crack the Enigma code. The computer was called Colossus and was built by Alan Turing. This image shows the circuitry and pulley-wheel system of the Colossus computer. (Photo by SSPL/Getty Images)

One of the operations that was planned by the Allied Troops was the D-Day landings in Normandy France. The plan was to land at various places on the coast of France and break down the German defences. This involved a lot of organisation and practise as troops would have to leave from all over England to land in France at the same time. This photo shows troops coming ashore during training exercises practising for the real thing. (Photo by Keystone/Getty Images)

Crouched low in the landing craft with weapons at the ready, these soldiers speed through rough seas to the 'attack', during invasion rehearsals. (Photo by Keystone Features/Getty Images)

Some US troops destined for the D Day landings were stationed in Falmouth leading up to the attack. Like elsewhere in England they also trained and prepared for the the invasion. This photo shows a US Army convoy passing the Red Lion at Mawnan Smith, near Trebah, during the run-up to the D-Day embarkation in June 1944.

Polgwidden Cove at Trebah Beach was to be the site at which the US troops embarked for Normandy. A road was built by the US troops from nearby Mawnan Smith which enabled them to drive straight onto the beach. The road is still there today.

7,500 American servicemen of the 29th Infantry Division embarked at Trebah on 31st May 1944 bound for the Normandy beaches.

At the same time US troops were ready to board landing ships at Weymouth, England for the D Day Normandy Invasion 1944. (Photo by: Universal History Archive/UIG via Getty Images)

A U.S. Army GMC truck embarking on a landing ship, tank (LST) at Portland Harbour, Devon for the invasion of Normandy, June 1944. GIs and others are watching. LST-134 in the background is scheduled to depart for Omaha Beach (Easy Red), France. It is part of Group 30 of LST Flotilla 12. (Photo by Galerie Bilderwelt/Getty Images)

US troops on the Esplanade at Weymouth, Dorset, on their way to embark on ships bound for Omaha Beach for the D-Day landings in Normandy, June 1944. (Photo by Galerie Bilderwelt/Getty Images)

Nearly 160,000 troops crossed the English Channel for D Day. This image shows US soldiers on a landing craft on their way to the Normandy beaches, during the invasion of Europe. (Photo by Keystone/Getty Images)

The Allied forces- made up of Canadian, British and US troops landed on five different areas of the coast- Utah, Omaha, Gold, Juno and Sword. This image shows the English troops arriving on the French coast. (Photo by: Photo12/UIG via Getty Images)

Operation Overlord was the code name for The Normandy Landings (D-Day). This image shows troops landing and making their way onto 'Nan Red' Beach, Juno Area, at St Aubin-sur-Mer at about 9 am on, 6 June 1944. (Photo by Lt. Handford/ IWM via Getty Images)

6th June 1944: US troops in landing craft, during the D-Day landings. (Photo by Keystone/Getty Images)

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

Troops landing at Omaha (Photo by © CORBIS/Corbis via Getty Images).

Landing of the allied troops on the beaches of Normandy, France, June 6, 1944, Second World War war, National archives, Washington, . (Photo by: Photo12/UIG via Getty Images)

Soldiers with the United States Navy 2nd Beach Battalion inspect radio-operated German Beetle tanks captured on Utah Beach during the Allied D-Day invasion of Normandy. German forces used the miniature tanks to pass supplies through dangerous areas and deliver bombs into enemy lines (Photo by © CORBIS/Corbis via Getty Images).

The surprise attack by the Allied Forces completely over took the German defences. Nearly 875,000 men had disembarked at Normandy by the end of June.

The beach was covered with `matting` and a pier built out into the deeper water to assist with the loading ofthe US Navy

This is a memorial at Trebah to the US troops who embarked here for the D Day Landings.

In this composite image a comparison has been made of La Breche, France today and an image of the British 2nd Army: Commandos of 1st Special Service Brigade landing on 'Queen Red' Beach, Sword Area, at la Breche, at approximately 8.40 am, 6 June 1944. (Photo by Capt. J L Evans/ IWM via Getty Images)