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What does the D in D-Day stand for? Why was 6 June 1944 so important?

Join IWM expert Holiday as she answers those questions and reveals some of the exciting secrets and stories behind D-Day. Discover the planning behind this top secret mission and what took place to make it happen.

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D-Day: People and Planning

Part of the Adventures in History series created during the UK lockdown in Spring 2020.


Hi there, my name is Holiday I work at Imperial War Museums. It's my job to seek out incredible stories from our collections and find exciting ways to share them with all of you.  

Today, I want to tell you about D-Day. Do you know what the D in D-Day actually stands for? Go on, have a think. Well, if you don't know, don't worry, I might just give you a hint later on. So, what is D-Day and why is it so important?  

Well, D-Day is seen as the beginning of the end of the Second World War. It marked the first step of the Allied powers' invasion of France, which would allow them to liberate Europe and to defeat Hitler and the Nazis. I think D-Day is really interesting because it's this incredible moment where all these different people trained to do different jobs and use different technology. They all came together to pull off this crazy complicated plan. There were so many things that could go wrong - and some things did go wrong but the Allies did manage to land in France, and they did manage to liberate occupied Europe.  

So, why was all of this necessary? Well, in the Second World War much of Europe was occupied by the Axis powers. In some countries, they had invaded, taken over and were in charge. The Allies planned to invade Europe to free them. As France is one of the closest countries to Britain, it made most sense to invade via the north coast in an area called Normandy. The only way to get to the coast of France is across the English Channel, so they had to travel there by sea or by air. So today we're going to talk about the biggest invasion in history and what it took to pull it off.  

So, who helped make D-Day happen? Well D-Day was an invasion plan by the Allies. Who were the Allies? Well, that's the UK, the USA and Russia - but it wasn't just these three countries, there were lots of other countries involved as well like Canada, Poland, Norway, the Czech Republic [Czechia] and Slovakia, which was then known as Czechoslovakia, as well as lots of other nations fighting all over the world who weren't involved on D-Day. The supreme commander was an American like me and he was called General Dwight D Eisenhower or Ike for short. He worked to plan the naval sea and land operations for D-Day from a place called Portsmouth in England. The men and women who worked with him were carefully selected and they worked in total secrecy to plan the invasion.  

So, have you got an answer for me yet? What do you think the D and D-Day stands for? Well, I'll let you in on a secret alright? Really it stands for...nothing. Nothing, it's just the day. I know but lots of grown-ups don't even know that so maybe you can go share your new-found fact with them.  

So how did D-Day happen? Well, there's an important thing in the military called logistics. This is a term that describes planning and whoa did D-Day require a lot of planning. There was everything from building the right boats to land on the beaches to developing a pipeline that would bring petrol all the way across the sea from France to England. There were people developing tricks to fool the enemy into thinking that the invasion was going to happen in different parts of the country and there were people like Ed in submarines, who were secretly choosing and marking each of the beaches ready in time for the invasion.  

When some people think of D-Day, they think of sailors, soldiers and pilots but really there were so many different important jobs involved. Everything from accountants to painters and seamstresses, all these different people working together as part of one big team.  

Now, despite how meticulously planned they were, there was still one thing that was out of their control and that was the weather. This mission required the perfect weather conditions? So, what were those perfect conditions? Well, they needed to have a full moon because on the night before D-Day paratroopers would jump into France and they needed the moonlight to help them to see. They needed the tide of the sea to be low and slow to help the landing craft to arrive onto the beaches. They needed it not to be too wet otherwise the sand would have gotten all muddy and sticky and gross. So, have a look out your window now - what's the weather like? Do you think that today would have been a good day to launch D-Day? Because the weather was so important, D-Day actually had to be delayed. On the day they planned, it would have been rainy and stormy, and the mission wouldn't have been successful, in fact it would have been a disaster. So, they waited until the following day when better conditions were predicted.  

So, how did they know what the weather was going to be like? Well just like you or me when we check apps or the news to see what the weather will be like, they consulted weather reports put together by a meteorologist or a weather scientist. The Women's Auxiliary Air Force or the WAAFs hired women to work in the Met Office during the war. At IWM we have letters from WAAFs who wrote to their friends describing their jobs. WAAFs in the Met Office would take observations of the weather every single hour and use these to create weather charts. They had to be really exact in these measurements as their predictions could potentially decide the success or failure of the whole mission. Their meteorological team was headed up by group Captain James Stagg. It was Stagg's job to review the weather reports and let the commander Eisenhower know when would be a good day to launch the invasion in the summer of 1944. He was the one who forecast the weather in the weeks leading up to D-Day and it was Stagg who predicted that temporary break in the bad weather, which allowed them to go ahead on the 6th of June. What a responsibility Stagg had. There were tens of thousands of people all relying on him to make the right decision. Can you imagine that? Next time you see a weather person on the news? Think about how many people must be relying on their predictions to be a hundred percent accurate - that's a lot of pressure isn't it? 

Now, we mentioned earlier about the D in D-day but that wasn't the only code word that was used. All of the beaches where they planned to land in France were given special code names like Utah, Gold and Sword and the whole operation was called Overlord. Operation Overlord - it makes it sound pretty exciting, doesn't it? But it wasn't just for fun these special names helped them to keep the mission secret and ensure that the enemy would be surprised. As well as secret code names, they organised an entire fake invasion plan to draw attention away from Normandy, so the occupying Germans would spread their defences across France.  

This fake invasion plan was called Operation Fortitude and involved devising loads of weird and wonderful ways to confuse and distract the enemy. Some of these were quite simple like dropping loads of little metal strips out of aircraft – kind of like these. So little metal strips like this would be dropped from aircraft and they would show up on the enemy's radar machines. So, to them it would look like there were loads of aircraft all around when really it was just little metal strips. It seems too simple, but it really worked. They also created dummy parachutists that were potato sacks with faces drawn on them called Ruperts and they created inflatable tanks that they could move to different locations to make it look like they were going to attack in other places.  

So, after all of this preparation, we get to the most important part - the invasion itself. And the most important part of this invasion is the landing onto the beaches. But how do you choose where to land and why does it need to be a beach? Well, the enemy expected that the Allies would land on a port since it's easier to unload your cargo and troops. Whereas it's much more difficult if you land on a beach to get things from big ships all the way onto the shore but there was one thing that they didn't expect. They didn't know that the Allies had a new piece of technology, a Mulberry Harbour. It works kind of like a bunch of Lego because it's all these small pieces that you put together once you get where you're going and it works like a floating port, a place where ships can dock, and unload and it means you can make your port anywhere. It only took them seven days to get it working which is pretty incredible. Do you have a port or harbour near where you live? How long do you think it took them to build? I bet it took longer than seven days.  

So, after all this work, they can't just land on any beach because the beaches have to be sandy but not too sandy or the big heavy equipment and trucks will get stuck. So, they have to be really, really picky about which specific beach they choose. So how did they choose these beaches? Could they go look at loads of satellite images on Google back in 1944? No. Well pretty quickly the British government realized they needed some help, so they put a call out to the public and asked people to send in their holiday photos and postcards from the beaches of northern France. Kind of like this one? Have you sent these to your family or your friends before when you go on a trip? Well, the British government had to use them to try and study the beaches and figure out what they were like? Can you imagine that? Nowadays it's so easy for us to just do a quick Google search and we can learn loads about what a place looks like but back then it was much, much harder. As well as finding the perfect beaches, they also had to figure out a way to get their ships there undetected.  

So, it was really important that all of the ships arrived under cover of darkness at night and remember this invasion, was also being fought from the air, so that meant that all the Allied aircraft had to arrive at night. This made it much harder for the enemy to spot them, but it was far more challenging for the pilots to see where they're going. As you can imagine, it's not so easy to fly a plane in the dark.  

Bud Rice with a pilot of a Dakota aircraft that dropped paratroopers on D-Day. He remembers how challenging it was to fly on the morning of D-Day as there was a heavy fog. His aircraft had special stripes on its wings as did all Allied aircraft and this helped them to identify each other through the darkness and the fog.  

Duke Boswell was a paratrooper who jumped from a Dakota, just like the aircraft of Bud flew on D-Day. Thousands of paratroopers like Duke jumped on D-Day. A Paratrooper is a special kind of soldier and they get to the battlefield by jumping out of an aircraft. Looking out of his Dakota on D-Day Duke remembers the scale of the invasion. He said that the ocean was full of ships - big ones, little ones, every kind of ship looked as if it was heading for France and that the sky was full of airplanes, all kinds. And he said that that's when he knew that they must win this war with all of the force that they had.  

D-Day was the most complicated land sea and air invasion ever attempted. There were so many different people and different kind of jobs involved. Far more than we could mention today. You can find out more about D-Day on IWM's website. Even with the incredible scale of planning and preparation that went into D-Day lots of people on all sides lost their lives. But the Allies did get ashore, they did clear the beaches and they did begin to advance into Europe. And that is also pretty amazing. On D-Day the Allies did get a foothold but it took them nearly a year to complete the mission to liberate Occupied Europe and that didn't happen until May of 1945, almost 11 months after the first day of the invasion on the 6th of June 1944. It took so many different people working together to make sure that D-Day was a success. But you know it's not just complex military operations that need lots of specialist brains to make them work.  

Take this humble tin of beans from my kitchen cupboard? How many different people do you think had to work together to get these beans to me? A farmer would have harvested them, a factory worker would have cooked them and put them in his tin, I guess a truck, or a train driver would have had to transport them and finally a shopkeeper would have sold them to me. All of those different people work together just to get this into my kitchen. It's almost like magic, isn't it? But it's not really magic, it's people! And amazing things can happen when people work together. So, have a think about some of the things in your house - how many different people had to work together to get those things all the way to you?  

If hearing about D-Day today has sparked your imagination you can send your questions through to IWM Facebook, and Twitter channels and we will come back to you. While you're online, why not subscribe to our YouTube channel so don't miss out on any future episodes of Adventures in History. Imperial War Museums is a charity. If you're able to donate help support our work bringing history to life, please head to our website to find out more. 

Next week you'll meet my friend Ngaire, who will tell you all about the trenches of the First World War. Thanks for joining me adventurers and I hope to see you soon! 

Curriculum Links and Learning Objectives

  • KS2 - A significant turning point in British history: D Day.                              

  • KS3/4 - Challenges for Britain, Europe and the wider world, 1901-present.   

  • To understand the scale and operations of D-day; the countries and people involved. 

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