Imagine the largest amphibious assault in history with tens of thousands of supplies, troops, and weapons landing in Normandy, France! On June 6, 1944, despite bad weather and multiple setbacks, armies, navies, and air support across the Allied forces came together to execute one of the most important invasions in World War II. The assault became known as D-Day, codenamed Operation Overlord, and would alter the outcome of the entire war! Continue reading to see how the invasion was the turning point of WWII!
Operation Overlord WW2
In 1944 Allied forces invaded Normandy, France, in the largest amphibious invasion in history.
Fig. 1 - Omaha Beach, June 6, 1944
The invasion, officially named "Operation Overlord," began on June 6, 1944, in an attempt to liberate France from Nazi Germany. The assault consisted of the British, Canadian, and U.S. armed forces with roughly 7,000 ships and 850,000 soldiers. The invasion would last precisely two months, three weeks, and three days, ending on August 30, 1944.
Debate Over Operation Overlord
Fig. 2 - Stalin, Roosevelt, and Churchill at the Tehran Conference in December 1943
Not all of the Allied powers were on board with how and when Operation Overlord was planned. At the Tehran Conference in 1943, Stalin, Roosevelt, and Churchill met to discuss military strategy for the war. Throughout the discussions, the leaders argued over how to invade northern France. Stalin pushed for a much earlier invasion of the country, but Churchill wanted to strengthen the British and American forces in the Mediterranean. Churchill and Roosevelt (overriding his military counsel) agreed to first invade North Africa to open shipping in the Mediterranean.
To appease Stalin, Churchill suggested that forces move west of Poland, allowing control over critical German territory to be in Polish hands. In response to Operation Overlord, Stalin stated that a Soviet offensive would be launched simultaneously to stop Germans from entering the Western Front. The logistical incapability to carry out Operation Overlord in 1943 was accepted, and the estimated invasion time was projected for 1944. The Tehran Conference would go on to have further implications for postwar politics and influence the Yalta Conference at the war's end.
D-day: Operation Overlord
The invasion of Normandy took years of planning and work as military officials discussed how to land forces in Europe.
Training
Fig. 3 - Dwight D. Eisenhower talking to paratroopers before the D-Day invasion
Planning of the project intensified when Dwight D. Eisenhower became Supreme Commander of the Allied Expeditionary Force and took control of Operation Overlord.2 Due to a lack of resources crossing the channel was not planned until 1944. Though no official invasion time was known, over 1.5 million American forces arrived in Great Britain to participate in Operation Overlord.
Planning
Fig. 4 - British 2nd Army demolished beach obstacles before the invasion
You will enter the continent of Europe and, in conjunction with the other United Nations, undertake operations aimed at the heart of Germany and the destruction of her armed forces." -US Army Chief of Staff General George C. Marshall to General Eisenhower 1944
Allied forces kept up a successful deception campaign, keeping German forces expecting an assault at Pas de Calais. The deception was complete with a fake army, equipment, and tactics. The assault of Pas de Calais made tactical sense as it housed the German V-1 and V-2 rockets. German troops heavily fortified the area, fully expecting an all-out invasion. Hitler gave the task to Erwin Rommel, who built almost 2,500 miles of fortifications.
Did you know?
In the deception campaign, Allied forces led Germany to believe in several potential landing sites, including Pas de Calais and Norway!
Logistics
Fig. 5 - American wounded awaiting Red Cross ambulances
Due to the size and extent of Operation Overlord, the invasion became one of the most significant logistical undertakings in history. The number of men and supplies alone ranged in the tens of thousands. The number of supplies transported between the US and Britain reached almost two million tons before the invasion.1 Even with the massive logistical operation, efficiency was maintained with equipment and supplies awaiting each unit when they arrived in Britain.
It [Operation Overlord] required provision for the transportation, shelter, hospitalization, supply, training, and general welfare of 1,200,000 men who had to be embarked in the United States and transported across the submarine-infested Atlantic to the United Kingdom." - George Marshall, Operation Overlord, Logistics, Vol. 1, No. 2
After getting soldiers and supplies to their assigned location, various equipment, camps, and field hospitals had to be set up. For example, training and housing buildings had to be built before troops' arrival. Normandy also posed a problem with a lack of large ports, and artificial ones had to be made.
Invasion
Fig. 6 - British troops walking up the gangway of SS Empire Lance on the way to France
Though D-day had extensive planning, invasion day did not go according to plan. The date of the invasion hit several delays and changes, and on June 4, the operation was delayed due to weather conditions. As the weather cleared, Eisenhower cleared the operation to begin on June 6, 1944, and paratroopers began landing. Even with the assault location unknown to the Germans, American forces encountered resistance at Omaha beach.
On Omaha beach, well over 2,000 Americans lost their lives but successfully established a hold on Normandy's coast. On June 11, the beach at Normandy was secured with over 320,000 forces, 50,000 military vehicles, and tons of equipment. Over June, Allied forces purged through the dense French terrain and captured Cherbourg, a critical port to bring in reinforcements.
D-Day Casualties
| Country | Casualties |
| United States | 22,119 (including killed, missing, prisoners, and wounded) |
| Canada | 946 (335 were listed as killed) |
| British | estimated 2,500-3,000 killed, wounded, and missing |
| German | estimated 4,000-9,000 (sources vary on the exact number) |
Operation Overlord: Map
Fig. 7 - Naval Bombardments on D-Day 1944
The map above depicts the naval bombardments of all allied forces during the Operation Overlord assault.
Operation Overlord: Outcome
After the Allies established a hold on Normandy beaches, a quick push forward was expected.
Fig. 8 - Troops about to storm Omaha Beach
However, Normandy's natural landscape and terrain proved difficult for soldiers. The German use of Normandy's natural hedgerows significantly slowed Allied forces, dragging the campaign out. Yet, the Normandy invasion landed a significant blow on the Nazi forces stopping the Germans from gathering more troops. Hitler attempted one last push with the Battle of the Bulge, where he launched a surprise attack. However, after air attacks on German forces, the battle ended. Hitler committed suicide on April 30th, and on May 8, 1945, Nazi Germany surrendered to Allied forces.
Fig. 9 - Duplex Drive tank used in Operation Overlord
The Swimming Tank
Along with invasion preparations, new weapons were introduced to aid in taking the Normandy beaches. The U.S. Army introduced a "swimming tank" called the Duplex Drive. An inflatable canvas skirt surrounding the tank allowed it to float on the water. Thought to be the ultimate surprise weapon, a group of twenty-eight were sent to support the troops in the D-day invasion. Unfortunately, the Duplex Drive was an abysmal failure from the beginning. Two decades after Operation Overlord, Dwight Eisenhower commented on the failure stating:
The swimming tanks that we wanted to have, to lead the attack-out of one group of 28 of them, 20 of them just turned over and drowned at the bottom of the ocean. Some of the men, fortunately, got out. Everything was going wrong that could go wrong." -Dwight D. Eisenhower
Only two swimming tanks made it ashore, leaving the troops without reinforcements. The tanks still sit at the bottom of the English Channel to this day.
Operation Overlord Significance
Many battles are forgotten over time, but D-day is prominent in history.
Fig. 10 - Normandy Supply Lines
Operation Overlord was a significant turning point for World War II and the Allied Powers. Less than a year after the invasion Nazi Germany surrendered to the Allies. The invasion of Normandy marked the beginning of the end of WWII and the liberation of Western Europe. Even though Nazi Germany continued fighting the war in the Battle of the Bulge, Adolf Hitler lost the upper hand with the success of Operation Overlord.
Operation Overload - Key Takeaways
- Operation Overlord was the codename for the D-Day invasion on June 6, 1944
- Allied forces combined their army, air, and naval forces, making it the largest amphibious invasion in history.
- Though intense planning went into Operation Overlord, it hit significant setbacks, including deteriorating weather conditions and loss of equipment (ie: tanks)
- Operation Overlord became the turning point for WWII. Shortly after the successful invasion, Hitler committed suicide on April 30th, followed by Nazi Germany's formal surrender on May 8.
References
- 1. George C. Marshall, Operation Overlord, Logistics, Vol. 1, No. 2 January 1946 2. D-Day and the Normandy Campaign, World War II National Museum, New Orleans
- D-Day and the Normandy Campaign, World War II National Museum, New Orleans
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