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D-Day (Normandy landings)
June 6, 1944· Battle· Europe
Well documentedSolid records, physical evidence or scientific consensus.
The Allied invasion of German-occupied France on June 6, 1944, the largest seaborne invasion in history.
See it on the Battles & Wars map →What happened
After two years of planning (Operation Overlord), about 156,000 American, British, Canadian and other Allied troops landed on five Normandy beaches, code-named Utah, Omaha, Gold, Juno and Sword, or dropped by parachute and glider behind them. Nearly 7,000 vessels and over 11,000 aircraft took part. A deception plan (Fortitude) convinced Germany the main blow would come near Calais. Omaha was the bloodiest beach. Allied casualties that day were about 10,000, including about 4,400 dead. Paris was liberated on August 25.
Why it matters
It opened the western front Stalin had demanded, forced Germany into a two-front war, and meant western Allied armies, not only Soviet ones, would liberate western Europe.
How we know
Allied plans and after-action reports, German records, wartime film and photographs, remains of the artificial Mulberry harbor at Arromanches, and the US National D-Day Memorial's count of 4,414 Allied dead.
Still debated
Whether an invasion could have succeeded in 1943, as Stalin urged, and how close Omaha Beach came to failure, are still debated.
Inside this (2)
Connections (12)
▸Gallipoli campaign taught amphibious lessons later used on D-Day (Normandy landings)Mostly agreed
The connection
Gallipoli's failed 1915 landings showed how an amphibious assault could go wrong without specialized landing craft, coordinated naval gunfire, unified command and good intelligence. Between the wars the US Marine Corps studied it closely to build its amphibious doctrine, and Allied planners for Normandy addressed each of those failures with purpose-built craft and massive preparation.
When and how
Gallipoli peninsula, Ottoman Turkey, 1915; studied at US Marine Corps schools at Quantico in the 1920s–30s; applied in Normandy, June 1944.
How sure are we?
Marine Corps doctrine, notably the 1934 'Tentative Manual for Landing Operations', drew explicitly on Gallipoli case studies.
Debates and open questions
The 1942 Dieppe raid and earlier landings in North Africa, Sicily and Italy taught Overlord's planners more directly; Gallipoli's influence was real but indirect.
▸D-Day (Normandy landings) opened a second front in World War IIWell documented
The connection
D-Day opened the western front Stalin had demanded since 1941. With Soviet armies advancing from the east and Allied armies from the west, Germany faced a two-front war it could not sustain. Paris was freed in August 1944, and Allied troops reached Germany's border by September.
When and how
Normandy, France, June 6, 1944, under Eisenhower's command; the Soviets launched their huge Operation Bagration in Belarus about two weeks later.
How we know
Allied and German records show Germany forced to split its forces, though most German divisions still faced the Soviets.
Debates and open questions
How much D-Day shortened the war, given that most German forces and losses were on the Eastern Front, is debated.
▸D-Day (Normandy landings) led to Germany's last gamble at Battle of the BulgeWell documented
The connection
After breaking out of Normandy, Allied armies raced across France and Belgium until their supply lines stretched thin in autumn 1944. Hitler gambled that a surprise strike through the lightly held Ardennes could retake the port of Antwerp, split the British and American armies, and force a negotiated peace in the west.
When and how
From Normandy, June–August 1944, to the Ardennes of Belgium and Luxembourg, December 16, 1944.
How we know
Hitler's orders for the offensive (code-named Watch on the Rhine) and his generals' postwar testimony set out its aims.
Debates and open questions
German generals such as Rundstedt and Model thought reaching Antwerp unrealistic; why Hitler believed it could break the alliance is debated.
▸Fall of France and the Dunkirk evacuation was reversed four years later by D-Day (Normandy landings)Well documented
The connection
In 1940 the British army escaped at Dunkirk without its equipment, and much of France was occupied. Four years later Allied armies came back across the same Channel, joined by Free French forces and the French Resistance, and liberated Paris in August 1944.
When and how
Dunkirk, May–June 1940, and Normandy, June 1944; Charles de Gaulle's Free French movement, formed in London in 1940, joined the liberation.
How we know
Both events are fully documented; Overlord's planners built on hard lessons from 1940 and the 1942 Dieppe raid, insisting on air supremacy and bringing artificial harbors.
Debates and open questions
How much rescuing about 338,000 trained troops at Dunkirk mattered to Britain's ability to return in 1944 is a matter of debate.
▸Dwight D. Eisenhower was supreme Allied commander for D-Day (Normandy landings)Well documented
The connection
As Supreme Commander of the Allied Expeditionary Force, Eisenhower oversaw planning, coordinated land, sea and air forces from several nations, and, when forecasters predicted a brief break in a storm, gave the order early on June 5, 1944. The invasion went ahead the next day.
When and how
Southwick House near Portsmouth, England, early June 5, 1944, after chief meteorologist James Stagg forecast the break in the weather.
How we know
Accounts by Eisenhower, his staff and Stagg, and his handwritten note accepting full blame if the landings failed.
Debates and open questions
His exact words when giving the order differ among witnesses; versions include 'OK, let's go' and 'Okay, we'll go'.
▸Omaha Beach was the costliest landing of D-Day (Normandy landings)Well documented
The connection
Of the five D-Day beaches, Omaha came closest to failure and cost the most lives. Its trouble showed the risks of the whole Normandy plan, and holding it joined the American landing at Utah to the British and Canadian beaches to the east.
When and how
Normandy coast between Vierville-sur-Mer and Colleville-sur-Mer, June 6, 1944; US V Corps' 1st and 29th Infantry Divisions against the German 352nd and 716th Divisions.
How we know
Unit after-action reports and casualty returns: about 2,000–2,400 US casualties at Omaha against roughly 200 at neighboring Utah Beach.
Debates and open questions
Casualty totals for each beach are still being revised by researchers, and how close General Omar Bradley came to diverting later waves elsewhere is debated.
▸Battle of the Atlantic had to be won before D-Day (Normandy landings)Mostly agreed
The connection
An invasion of France needed about 1.5 million American troops and millions of tons of supplies shipped to Britain first. That was only possible once the U-boats were beaten in mid-1943. By June 1944 convoys crossed with few losses, and almost no U-boats got through to the Normandy invasion fleet.
When and how
North Atlantic convoy routes, mid-1943 to June 1944; Operation Bolero, the American buildup in Britain.
How sure are we?
Allied planning papers made winning the shipping war a condition for invasion, and US troop numbers in Britain rose sharply once losses fell.
Debates and open questions
Whether D-Day could have come in 1943, as Stalin and some US planners wanted, depends partly on how early the Atlantic was really secure.
▸Native American code talkers included Comanche signalers landing on D-Day (Normandy landings)Well documented
The connection
Code talking was not only Navajo or Pacific. Comanche soldiers in the US 4th Infantry Division's signal company landed at Utah Beach on D-Day, passing messages in Comanche, with a few coded words for military terms. Their work continued as the division fought inland across France and into Germany.
When and how
Utah Beach, Normandy, June 6, 1944; Comanche men recruited in Oklahoma in 1940, serving in the 4th Signal Company, 4th Infantry Division.
How we know
Army records and veterans' testimony, including Charles Chibitty, the last surviving Comanche code talker, who died in 2005; France honored the group in 1989.
Debates and open questions
Exactly how many Comanche signalers landed on D-Day, usually given as 13 or 14, and how heavily their code was used vary by account.
▸Electronic warfare (jamming and chaff) faked phantom invasion fleets during D-Day (Normandy landings)Well documented
The connection
On the night of June 5–6, 1944, RAF bombers dropped Window chaff in precisely timed patterns while small boats towed radar-reflecting balloons. On German screens this looked like invasion fleets heading for Cap d'Antifer and Boulogne, far from Normandy. Jammers also blinded many of the coastal radars facing the real invasion route.
When and how
English Channel, night of June 5–6, 1944; Operations Taxable and Glimmer, flown by RAF 617 and 218 Squadrons with Royal Navy launches.
How we know
RAF and Royal Navy operational records describe the deception; German war diaries record their confused responses.
Debates and open questions
German reactions were mixed; whether the phantom fleets actually drew forces away, or mainly added to the confusion, is uncertain.
▸Douglas Aircraft (SBD Dauntless, C-47) built the C-47s that dropped paratroopers before D-Day (Normandy landings)Well documented
The connection
On the night of June 5–6, 1944, over 800 Douglas C-47s, which the British called Dakotas, carried about 13,000 American paratroopers of the 82nd and 101st Airborne Divisions to Normandy, while others dropped British paratroopers. Clouds and anti-aircraft fire scattered many drops, but the paratroopers seized roads and bridges behind the beaches.
When and how
Airfields in southern England to the Cotentin Peninsula and east of the Orne River, Normandy, June 5–6, 1944; US IX Troop Carrier Command and RAF transport groups.
How we know
Troop carrier records, airborne divisions' after-action reports and veterans' accounts.
Debates and open questions
Whether the scattered drops helped by confusing German commanders, or mainly hurt the attack, is debated.
▸North American Aviation and the P-51 Mustang helped win the air supremacy needed for D-Day (Normandy landings)Mostly agreed
The connection
In 'Big Week' in February 1944 and the months after, Mustang-escorted bomber raids forced the Luftwaffe to fight and lose pilots it could not replace. On June 6, 1944, the Allies flew about 14,000 sorties over Normandy, while the Luftwaffe managed only a few hundred.
When and how
Over Germany and France, February–June 1944; US Eighth and Ninth Air Forces and RAF fighter units.
How sure are we?
Allied and German sortie counts for June 6, and Luftwaffe pilot-loss records from spring 1944.
Debates and open questions
Credit is shared with other fighters such as the P-47 Thunderbolt and with attacks on German oil; the Mustang's exact share is debated.
▸Liberty ships carried supplies and formed breakwaters for D-Day (Normandy landings)Well documented
The connection
Liberty ships carried many of the invasion's vehicles, fuel and ammunition across the Atlantic and then the Channel. Some old freighters, Liberty ships among them, were deliberately sunk off the beaches as 'Corncob' blockships, forming 'Gooseberry' breakwaters that sheltered landing craft and the Mulberry artificial harbors.
When and how
Normandy coast, June 1944; about 60 blockships scuttled off the five beaches, plus Liberty ships in the supply convoys.
How we know
Admiralty and US Navy records of the Mulberry operation list the ships scuttled; some wrecks are still visible at low tide.
Debates and open questions
How much the artificial harbors mattered, versus landing supplies over open beaches, is debated; the American Mulberry was wrecked by a storm in late June.