Preparation and Planning

Key Players

The planning of Operation Overlord and its implementation on June 6, 1944 involved many different components. One of those vital parts was the presence of able leadership. These men were tasked with such decisions as how many men would land on each beach and which ships they would use to cross the English Channel. Landing soldiers on the beaches of Normandy was not the end of their planning however. Allied leadership had to devote considerable attention to issues such as supply logistics to ensure a sufficient amount of food and medicine and establish secure lines of communication. Everything had to be prepared prior to landing in Normandy, even before the ships left Britain to cross the English Channel. Having the right leadership in place was essential to the success of Operation Overlord.

After the Allies decided on Normandy as the invasion point at the end of 1943 and set a date for May 1944, they appointed Dwight Eisenhower as Supreme Allied Commander of the Allied Expeditionary Force for the invasion of Europe. The determined general faced an enormous task and only had a few months to plan the operation on which many laid their hopes for decisively ending World War II. Working with the various personalities in Allied leadership made his task more difficult. Eisenhower and President Franklin D. Roosevelt did not always agree, and Eisenhower even struggled at times in his relationship with Winston Churchill. As D-Day approached, Eisenhower finally convinced the British prime minister that he could not accompany the invading force across the English Channel into Normandy on June 6.

Eisenhower dealt with other difficult personalities besides Roosevelt and Churchill. Because planning such a huge operation could not be done by one person, various other military figures received appointments as naval, air, and ground commanders. Trafford Leigh-Mallory was appointed to command the Air Forces of Allied Expeditionary Forces. While planning the invasion, he advocated the Transportation Plan; the Allied aircraft would focus on destroying the railway system throughout occupied France to ruin German supply and communication lines. Although Eisenhower approved this plan, Leigh-Mallory clashed with other Allied leaders about his strategy and tactics.

Both Arthur William Tedder and Carl Spaatz disagreed with Leigh-Mallory. Tedder had served as Air Commander in North Africa and was named Deputy Supreme Commander of the Normandy invasion in early 1944. His efforts to have the dominant air power in France conflicted with Leigh-Mallory due to an overlap in duties. Spaatz commanded the U.S. Strategic Air Force in Europe, and advocated a different air strategy for France than Leigh-Mallory. Contrary to the Transportation Plan, Spaatz wanted to target German oil production and industry to cripple them. Eisenhower’s approval of the Transportation Plan over the Oil Plan likely did not elevate Leigh-Mallory in Spaatz’s opinion.

Leaders were needed for ground and naval forces as well. Bertram Ramsay was appointed Naval Commander-in-Chief of the Allied Naval Expeditionary Force. He oversaw Operation Neptune, the amphibious landing of Operation Overlord. His position as Deputy Naval Commander in North Africa and Operation Husky in Sicily provided him with the experience to plan an amphibious assault on the Normandy beaches. Bernard Montgomery was placed in charge of the Allied ground forces for D-Day. Eisenhower’s preference was General Harold Alexander for that position, but he diplomatically gave the appointment to Montgomery and even approved his plan for expanding the invasion force and landing area. Montgomery commanded the British and Canadian 21st Army Group as well.

Other prominent military leaders involved in the planning of Operation Overlord were Omar Nelson Bradley, Miles Dempsey, and even George Patton. Bradley was appointed to command the 1st U.S. Army in the invasion, and Montgomery selected Dempsey to command the mixed British and Canadian 2nd Army. Because the Germans considered Patton central to any plan to invade Europe, the Allies made him a prominent figure in the deceptive Operation Fortitude. Through Fortitude, they successfully fed the Germans false intelligence including Patton’s name to throw them off the true preparation of Operation Overlord.

Even with exceptional leadership, planning and practice for such a large invasion does not always go smoothly. Eisenhower and the Allied leaders postponed D-Day from the beginning of May to June 5. They later postponed the invasion one last time just a few days before implementation due to bad weather. Lack of landing craft and supplies ended the hope of launching an invasion of southern France, Operation Dragoon, at the same time as Operation Overlord. Dragoon was postponed until later in the summer. Even rehearsal of the invasion encountered problems. On April 28, 1944, Exercise Tiger took place off the British coast at Slapton Sands. German E-boats intercepted the large convoy and hit three ships with torpedoes. Nearly 1,000 men were killed in the sinking or damaging of the three LSTs. Amidst the tragic loss of life in the rehearsal, Allied leadership worried that Allied soldiers might have fallen into German hands during the attack, and they nearly changed important operation details. Secrecy was so vital that families did not even know how their loved ones died. One British mother did not learn how her son really died until forty years later while watching a documentary about Exercise Tiger and making a connection between the dates. Operation Overlord remained a secret despite the disaster.

Despite the daunting task facing the Allies, the military leadership managed to plan and prepare for the eventual success of the Normandy invasion. Eisenhower skillfully navigated the various personality types of military commanders and politicians, and he approved the necessary plans for the operation. Montgomery, Tedder, Spaatz, Leigh-Mallory, and others carried out their portions of the operation as expected by their leader. Leadership maintained the secret of Operation Overlord, and the Germans remained oblivious to the true invasion site.

Normandy Chosen

The need for a cross-channel invasion to liberate France was recognized early during the war. Although this necessity was understood, actually finding a suitable route took extensive preparation. While the Allies were considering invasion sites, the BBC broadcasted an appeal for any information about geography, enemy defenses, and presence along the coast. The public response was stunning in its abundance. Millions of postcards and photographs provided data that helped influence the choice of an invasion site. Geographically, the beaches of Normandy appeared to be the best landing sites. Normandy allowed a gateway to the European continent and an exit from the mainland to the British Isles.

Normandy was chosen as the invasion site, but many strategic and geographical considerations were evaluated. Among them were the nature of the beaches, moon phases and tidal range, sites of airfields, sailing distances from channel harbors, and the selections of ports to be captured. Another major characteristic to research was the strength of German defenses at certain vital points. A dominant German defense along France’s beaches was the Atlantic Wall. The Atlantic Wall was a series of concrete fortifications that Hitler had ordered to be built along the coast. Although the wall was incomplete in 1944, it was still a fierce defensive structure. Normandy was favorable when considering the Atlantic Wall because it had many weak sections.

Another geographical reason for choosing Normandy was its location in proximity to the Isle of Wight. The Isle of Wight had naval ports and railways in southern England that were away from major civilian populations. This allowed an easier route for the movement of troops and supplies while planning for the invasion. The waterways in the area also provided suitable cover to hide the invasion vessels. The beaches of Normandy were geographically close to the port of Cherbourg as well. This city was deemed essential to capturing supply routes that could help further the invasion once the beaches were overtaken.

After the geographical site was decided, the date of the invasion was the next major decision to be made. The date would be based on moon phases and the weather. The most skilled meteorologists were chosen to help decide the appropriate invasion date. The prevalent issue would be the limitations of long-range forecasting, which first came into play during the North African landings in 1942. The Allied army wanted a high tide to shorten the amount of exposed sand as the soldiers stormed the beach.  The Allied navy wished for the water to be low, so that items, such as mines, could be identified and cleared. The Allies determined that a full moon would be needed for a successful operation. The meteorologists decided that the desired conditions were only available for about six days each month as well. Based on all the information gathered by the meteorologist and geologist teams, the date of June 5 was initially selected.

Soon enough though, the weather during the projected June 5 landing seemed to show that air support would be useless and the boat landings would be difficult. The meteorologists decided that the weather window after June 5 would allow a thirty-six-hour period of suitable weather. The weather was still not perfect the day of Operation Overlord, but it allowed the Allies to gain the footing they needed on the European mainland.

Operation Fortitude

The Allies wanted to give Overlord the best chance for success they could. The planners thought it would be helpful to set up decoy operations to trick or confuse the Germans. The code name for this deception was Operation Fortitude and the operation consisted of many different parts. The main goal of Fortitude was to convince the Germans the cross channel invasion was to be aimed at Norway or Pas de Calais in Northern France. This was not the first time the Allies used deception to aid in military operations but it would be one of the most successful uses of military deception during World War II.
Operation Fortitude South was created to convince the German’s that the landing force was bigger than it actually was. Fortitude South created a fake US army group, First Army Group. This group was “based” out of southeast Britain. The Allies supplied this group with faux equipment such as inflatable tanks and gave fake radio signal and movement commands to make the Germans believe there would be a large invasion at Pas de Calais, Northern France. At night the men would play recordings of airplane engines starting up over a loud speaker. Automobile lights were also attached to carts and men would run up and down fake runways to make it appear like planes were taking off and landing. During the daytime the “planes” themselves were nothing but canvas and tubing. Fortitude South also wanted to contain information of the actual buildup of Allied troops in Southern Britain preparing for the true invasion. The Allies had to create eleven faux divisions, that is 40,000 to 60,000 imaginary men. Spies played a key role in sharing this information to Nazi command. Two agents named Garbo and Brutus played a key role in delivering convincing information to Hitler and his leadership.

Likewise, the goal of Fortitude South was to convince German leaders of the Allied plans to invade Norway. The false plans to invade Norway and then push into Germany had to look official and convincing. British General Sir Andrew Thorne was selected for the task of “commanding the invasion into Norway.” The Allies then turned to the use of double agents, men claiming to work as spies for Germany when they were truly employed by the Allies, to spread the false intelligence. The two spies who would do the majority of the work for Fortitude North were given the code names Jeff and Mutt.

Fortitude South also featured the well-known General George Patton. Patton was selected largely due to the reputation he had among American and German leaders. Patton, who at the time Fortitude South was being planned, was in charge of the US Third Army. In order for the plan to look fluid, Patton was “removed” from command and a replacement general plugged in his place. Patton’s flamboyant character and philosophy of war earned him great respect among the German Army and greatly added to the success of Operation Fortitude.

The impact of Operation Fortitude played a key role in the success of the D-Day landings. Hitler sent troops out of France into Norway, convinced the Allied invasion would take place there. Hitler would still be holding onto this belief on June12; he was certain the main invasion would come from Norway. Fortitude would continue to function until 1945. However, the further the Allied troops pushed into Germany, the less the Allies needed the hoax to stay in place. Operation Fortitude proved the dedication Allied commanders had to giving the true invasion at Normandy the best chance possible. Operation Fortitude helps illustrate the vast dynamics of Operation Overlord and the cost of a successful invasion.