Battles
Operation Neptune
The Normandy landings were the landing operations and associated airborne operations on Tuesday, 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during World War II. Codenamed Operation Neptune and often referred to as D-Day, it was the largest seaborne invasion in history. The operation began the liberation of German-occupied France (and later western Europe) and laid the foundations of the Allied victory on the Western Front.
Background
After the German Army invaded the Soviet Union in June 1941, the Soviet leader Joseph Stalin began pressing his new allies for the creation of a second front in western Europe.[12] In late May 1942 the Soviet Union and the United States made a joint announcement that a "... full understanding was reached with regard to the urgent tasks of creating a second front in Europe in 1942."[13] However, British Prime Minister Winston Churchill persuaded US President Franklin D. Roosevelt to postpone the promised invasion as, even with US help, the Allies did not have adequate forces for such an activity.[14]
Instead of an immediate return to France, the western Allies staged offensives in the Mediterranean Theatre of Operations, where British troops were already stationed. By mid-1943 the campaign in North Africa had been won. The Allies then launched the invasion of Sicily in July 1943, and subsequently invaded the Italian mainland in September the same year. By then, Soviet forces were on the offensive and had won a major victory at the Battle of Stalingrad. The decision to undertake a cross-channel invasion within the next year was taken at the Trident Conference in Washington in May 1943.[15] Initial planning was constrained by the number of available landing craft, most of which were already committed in the Mediterranean and Pacific.[16] At the Tehran Conference in November 1943, Roosevelt and Churchill promised Stalin that they would open the long-delayed second front in May 1944.[17]
Meeting of the Supreme Headquarters Allied Expeditionary Force (SHAEF), 1 February 1944. Front row: Air Chief Marshal Arthur Tedder; General Dwight D. Eisenhower; General Bernard Montgomery. Back row: Lieutenant General Omar Bradley; Admiral Bertram Ramsay; Air Chief Marshal Trafford Leigh-Mallory; Lieutenant General Walter Bedell Smith.
The Allies considered four sites for the landings: Brittany, the Cotentin Peninsula, Normandy, and the Pas-de-Calais. As Brittany and Cotentin are peninsulas, it would have been possible for the Germans to cut off the Allied advance at a relatively narrow isthmus, so these sites were rejected.[18] With the Pas-de-Calais being the closest point in continental Europe to Britain, the Germans considered it to be the most likely initial landing zone, so it was the most heavily fortified region.[19] But it offered few opportunities for expansion, as the area is bounded by numerous rivers and canals,[20] 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 eventually into Germany. Normandy was hence chosen as the landing site.[21] The most serious drawback of the Normandy coast—the lack of port facilities—would be overcome through the development of artificial Mulberry harbours.[22] A series of modified tanks, nicknamed Hobart's Funnies, dealt with specific requirements expected for the Normandy Campaign such as mine clearing, demolishing bunkers, and mobile bridging.[23]
The Allies planned to launch the invasion on 1 May 1944.[20] The initial draft of the plan was accepted at the Quebec Conference in August 1943. General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force (SHAEF).[24] General Bernard Montgomery was named as commander of the 21st Army Group, which comprised all land forces involved in the invasion.[25] On 31 December 1943 Eisenhower and Montgomery first saw the plan, which proposed amphibious landings by three divisions with two more divisions in support. The two generals immediately insisted that the scale of the initial invasion be expanded to five divisions, with airborne descents by three additional divisions, to allow operations on a wider front and to speed the capture of Cherbourg.[26] The need to acquire or produce extra landing craft for the expanded operation meant that the invasion had to be delayed to June.[26] Eventually, thirty-nine Allied divisions would be committed to the Battle of Normandy: twenty-two US, twelve British, three Canadian, one Polish, and one French, totalling over a million troops[27] all under overall British command.[28]
Weather
The invasion planners determined a set of conditions involving the phase of the moon, the tides, and the time of day that would be satisfactory on only a few days in each month. A full moon was desirable, as it would provide illumination for aircraft pilots and have the highest tides. The Allies wanted to schedule the landings for shortly before dawn, midway between low and high tide, with the tide coming in. This would improve the visibility of obstacles on the beach, while minimising the amount of time the men would be exposed in the open.[41] Eisenhower had tentatively selected 5 June as the date for the assault. However, on 4 June, conditions were unsuitable for a landing: high winds and heavy seas made it impossible to launch landing craft, and low clouds would prevent aircraft from finding their targets.[42]
Surface weather analysis map showing weather fronts on 5 June
Group Captain James Stagg of the Royal Air Force (RAF) met Eisenhower on the evening of 4 June. He and his meteorological team predicted that the weather would improve enough for the invasion to proceed on 6 June.[43] The next available dates with the required tidal conditions (but without the desirable full moon) would be two weeks later, from 18 to 20 June. Postponement of the invasion would have required recalling men and ships already in position to cross the Channel, and would have increased the chance that the invasion plans would be detected.[44] After much discussion with the other senior commanders, Eisenhower decided that the invasion should go ahead on the 6th.[45] A major storm battered the Normandy coast from 19 to 22 June, which would have made the beach landings impossible.
Allied control of the Atlantic meant German meteorologists had less information than the Allies on incoming weather patterns.[39] As the Luftwaffe meteorological centre in Paris was predicting two weeks of stormy weather, many Wehrmacht commanders left their posts to attend war games in Rennes, and men in many units were given leave.[46] Field Marshal Erwin Rommel returned to Germany for his wife's birthday and to meet with Hitler to try to obtain more Panzers.
Order of Battle
Allied order of battle
Commander, SHAEF: General Dwight D. Eisenhower
Commander, 21st Army Group: General Bernard Montgomery
US zones
Commander, First Army (United States): Lieutenant General Omar Bradley
The First Army contingent totalled approximately 73,000 men, including 15,600 from the airborne divisions.
Utah Beach
VII Corps, commanded by Major General J. Lawton Collins
4th Infantry Division: Major General Raymond O. Barton
82nd Airborne Division: Major General Matthew Ridgway
90th Infantry Division: Brigadier General Jay W. MacKelvie
101st Airborne Division: Major General Maxwell D. Taylor
Omaha Beach
V Corps: Major General Leonard T. Gerow
1st Infantry Division: Major General Clarence R. Huebner
29th Infantry Division: Major General Charles H. Gerhardt
British and Canadian zones
Overall, the Second Army contingent consisted of 83,115 men, 61,715 of them British.[11] The nominally British air and naval support units included a large number of personnel from Allied nations, including several RAF squadrons manned almost exclusively by overseas air crew. For example, the Australian contribution to the operation included a regular Royal Australian Air Force (RAAF) squadron, nine Article XV squadrons, and hundreds of personnel posted to RAF units and RN warships.[82] The RAF supplied two-thirds of the aircraft involved in the invasion.[83]
Gold Beach
XXX Corps: Lieutenant General Gerard Bucknall
50th (Northumbrian) Infantry Division: Major General D.A.H. Graham
Juno Beach
3rd Canadian Division: Major General Rod Keller
Sword Beach
British I Corps, commanded by Lieutenant General John Crocker
3rd Infantry Division: Major General Tom Rennie
6th Airborne Division: Major General R.N. Gale
79th Armoured Division: Major General Percy Hobart
provided specialised armoured vehicles which supported the landings on all beaches in Second Army's sector.