Operation Overlord - Preparations For D-Day

Preparations For D-Day

In June 1940, German dictator Adolf Hitler had triumphed in what he called "the most famous victory in history" – the fall of France. The British, although besieged, had been spared from annihilation when Operation Dynamo evacuated 300,000 troops from Dunkirk. The British Prime Minister Winston Churchill, in one of his famous speeches, vowed to invade France and liberate it from Nazi Germany ( Quotations related to God Protect France at Wikiquote).

In a joint statement with the Soviet premier Communist Party General Secretary Joseph Stalin and American President Franklin D. Roosevelt, Churchill announced in 1942 a "full understanding" concerning the urgent task of creating a second front in Europe. Churchill unofficially informed the Soviets in a memorandum handed to Soviet Minister of Foreign Affairs Vyacheslav Molotov that the resources necessary for an invasion were lacking in 1942. However, the announcement had some effect as it caused Hitler to order preparations for an Allied descent on Europe.

The British, under Churchill, wished to avoid the costly frontal assaults of World War I - Churchill's previous experience of opening a second front via an invasion had been the disastrous campaign in Gallipoli, Turkey. Churchill and the British staff favoured a course of allowing the insurgency work of the Special Operations Executive to come to widespread fruition, while making a main Allied thrust from the Mediterranean Sea to Vienna and into Germany from the south, concentrating on the weaker Axis ally, Italy. Such an approach was also believed to offer the advantage of creating a barrier to limit the Soviet advance into Europe. However, the U.S. government believed from the onset that the optimum approach was the shortest route to Germany emanating from the strongest Allied power base: Great Britain. They were adamant in their view and made it clear that it was the only option they would support in the long term. Two preliminary proposals were drawn up: Operation Sledgehammer, for an invasion in 1942, and Operation Roundup, for a larger attack in 1943, which was adopted and became Operation Overlord, although it was delayed until 1944.

This operation will be the primary United States and British ground and air effort against the Axis of Europe. Following the establishment of strong Allied forces in France, operations designed to strike at the heart of Germany and to destroy her military forces will be undertaken. We have approved the outline plan for Operation Overlord. —Report by Allied Combined Chiefs of Staff, Quebec Conference, August 1943

The planning process was started in earnest after the Casablanca and Tehran Conferences with the appointment of British Lieutenant-General Frederick E. Morgan as Chief of Staff to the Supreme Allied Commander (Designate), a title shortened to COSSAC, with the American Major General Ray Barker as his deputy. The COSSAC staff's initial plans were constrained by the numbers of landing craft available, which were reduced by commitments in the Mediterranean and Pacific. In part because of lessons learned by Allied troops in the raid on Dieppe of 19 August 1942, the Allies decided not to assault a French seaport directly in their first landings. The short operating range of British fighters, including the Spitfire and Typhoon, from UK airfields greatly limited the number of potential landing sites, as comprehensive air support depended upon having planes overhead for as long as possible. Geography reduced the choices further to two sites: the Pas de Calais and the Normandy coast.

Normandy presented serious logistical problems, not the least of which was that the only viable port in the area, Cherbourg, was heavily defended. Many among the higher echelons of command argued that the Pas de Calais would make a more suitable landing area on these grounds alone. Although the Pas de Calais was the shortest distance to the European mainland from Britain, it was the most heavily fortified and defended landing site. It was also considered that it offered few opportunities for expansion as the area was bounded by numerous rivers and canals, whereas landings on a broad front in Normandy would permit simultaneous threats against the port of Cherbourg, coastal ports further west in Brittany, and an overland attack towards Paris and towards the border with Germany. Normandy was a less-defended coast and an unexpected but strategic jumping-off point, with the potential to confuse and scatter the German defending forces. Normandy was hence chosen as the landing site.

The COSSAC staff planned to launch the invasion on 1 May 1944. The initial draft of the COSSAC plan was accepted at the Quebec Conference in August 1943, but no supreme commander was appointed for several months. General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force (SHAEF) in November 1943. SHAEF was based in Camp Griffiss, Bushy Park, Teddington, south-west London, and had over 1200 military personnel. General Bernard Montgomery was named as commander of the 21st Army Group, to which all of the invasion ground forces belonged, and was also given charge of developing the invasion plan. Both Eisenhower and Montgomery first saw the COSSAC plan on 31 December 1943 at Marrakech in Morocco, in a conference with Winston Churchill. They insisted immediately that the scale of the initial invasion be expanded, to prevent the invaders being restricted to a narrow beachhead, with insufficient room to land follow-up formations and vulnerable to German counter-attacks. The need to acquire or produce extra landing craft for this expanded operation meant that the invasion had to be delayed to June.

The COSSAC plan proposed a landing from the sea by three divisions, with two brigades landed by air. Following Eisenhower's and Montgomery's revision of the plan, this was expanded to landings by five divisions and airborne descents by three divisions. In total, 39 divisions would be committed to the Battle of Normandy: 12 British, three Canadian and one Polish division under overall British command, and 22 American divisions and one Free French division, totalling over a million troops.