June 6, 1944 was the beginning of the end of WWII in Europe; France at the time was occupied by the armies of Nazi Germany and the combined land, air, and sea forces of the allied armies led to the liberation of France and the later defeat of the Germans.

While we focus on the coast of France, we sometimes overlook events on the other side of the world. That same day, June 6, 1944, a huge attack force cleared Pearl Harbor on its way to invade Japanese positions in the Mariana Islands. (NPR)

The WWII began when Britain and France declared war on Germany on September 15, 1939, following Germany’s invasion of Poland. Then in May 1940, Germany invaded France, Belgium, Holland, Norway and Denmark. A year later, Germany invaded the Soviet Union.

Japan attacked Pearl Harbor on December 7, 1941, leading the US top declare war on Japan.  Germany, in turn, declared war on the US, bringing America into the war in Europe.  WWII was being fought in the Pacific and Atlantic.

For years, Allied leaders and military planners had debated about when, where, and how to land troops in northern Europe. Although plans for such an action had been in the works for years, it was not until December 1943, when General Dwight D Eisenhower was appointed Supreme Commander of the Allied Expeditionary Force, that preparations for the future operation, code named Overlord, intensified.

Although the invasion was delayed with no definite timeline, American troops began arriving in Great Britain in record numbers in 1943. By the end of May 1944, there were more than 1.5 million US Army personnel in the United Kingdom to either participate in or support the cross-Channel action.  

For several months prior to the invasion, several thousand Allied bombers and fighters attacked targets from the Pas de Calais to the north to the French port of Cherbourg to the west and more than a hundred miles inland to isolate the Normandy area of operations and hamper the ability of German commanders to reinforce their forces in Normandy once the invasion began.

German High Command had bought into the deceptions of the operation, and fully expected a landing at the Pas de Calais. Planners instead had selected a 50-mile stretch of coastline in Normandy.

The Normandy beaches were chosen by planners because they lay within range of air cover and were less heavily defended than the obvious objective of the Pas de Calais, the shortest distance between Great Britain and the Continent.

The action was planned in two parts.  Neptune, the naval component and assault phase, involved moving tens of thousands of Allied troops across the Channel and landing them on the beaches while providing gunfire support.  Overlord was pivotal point of the plan – the invasion and the subsequent Battle of Normandy.

Approximately 160,000 Allied soldiers were to land across five beaches code named Sword, Juno, Gold, Omaha, and Utah, while British and American paratroop and glider forces landed inland.  Forces landing at each beach would eventually link up, establishing a beachhead from which to further push inland into France.

After numerous delays and major planning changes, D-Day was set for June 5. However, on June 4, as paratroopers prepared to board their aircraft to carry them behind enemy lines, weather conditions deteriorated.

The decision was made to delay 24 hours, requiring part of the naval force bound for Utah beach to return to port. With a small window of opportunity in the weather, Eisenhower made the decision to go – D-Day would be June 6, 1944.

In issuing the Order of the Day, Eisenhower stated, “Soldiers, Sailors and Airmen of the Allied Expeditionary Force! You are about to embark on the Great Crusade, toward which we have striven these many months.”

“The eyes of the world are upon you. The hopes and prayers of liberty-loving people everywhere march with you. In company with our brave Allies and brothers-in-arms on other Fronts, you will bring about the destruction of the German war machine, the elimination of Nazi tyranny over the oppressed peoples of Europe, and security for ourselves in a free world.”

“Your task will not be an easy one. Your enemy is well trained, well equipped and battle-hardened. He will fight savagely. …”

“The tide has turned! The free men of the world are marching together to Victory! I have full confidence in your courage, devotion to duty and skill in battle. We will accept nothing less than full Victory! Good luck! And let us all beseech the blessing of Almighty God upon this great and noble undertaking.”

Total Allied troops who landed in Normandy: 156,115 (including 23,400 Allied airborne troops); Soldiers’ home nations: United States, Britain, Canada, Belgium, Norway, Poland, Luxembourg, Greece, Czechoslovakia, New Zealand and Australia (+177 French commandos).

Total Allied aircraft that supported landings: 11,590; Total naval vessels in Operation Neptune: 6,939 (including Naval combat ships: 1,213; Landing ships / craft: 4,126; Ancillary craft: 736; Merchant vessels: 864 – of the 6,939 ships involved in D-Day, 80 percent were British; 16.5 percent, U.S.; and the rest from France, Holland, Norway and Poland.)

By June 30, over 850,000 men, 148,000 vehicles, and 570,000 tons of supplies had landed on the Normandy shores. Fighting by the brave soldiers, sailors and airmen of the allied forces western front, and Russian forces on the eastern front, led to the defeat of German Nazi forces. On May 7, 1945, German General Alfred Jodl signed an unconditional surrender at Reims, France.

“Many explanations have been given for the meaning of D-Day, June 6, 1944, the day the Allies invaded Normandy from England during World War II. The Army has said that it is ‘simply an alliteration, as in H-Hour.’  Others say the first D in the word also stands for ‘day,’ the term a code designation.”

“The French maintain the D means ‘disembarkation,’ still others say ‘debarkation,’ and the more poetic insist D-Day is short for ‘day of decision.’”

“When someone wrote to General Eisenhower in 1964 asking for an explanation, his executive assistant Brigadier General Robert Schultz answered: ‘General Eisenhower asked me to respond to your letter. Be advised that any amphibious operation has a ‘departed date’; therefore the shortened term ‘D-Day’ is used.”

That response reminds us that the invasion of Normandy on June 6, 1944 was not the only D-Day of World War II. Every amphibious assault – including those in the Pacific, in North Africa, and in Sicily and Italy – had its own D-Day.

While the focus of D-Day is on the coast of France, we sometimes overlook events on the other side of the world. That same day, June 6, 1944, a huge attack force cleared Pearl Harbor on its way to invade Japanese positions in the Mariana Islands. (NPR)

Since the fall of the Marshall Islands to the Americans a few months earlier, both sides began to prepare for an American onslaught against the Marianas and Saipan in particular. The Americans decided that the best course of action was to invade Saipan first, then Tinian and Guam.  The Battle of Saipan was under the code name Operation Forager.

The force that headed west across the Pacific may have been smaller in numbers than the armada that gathered off the coast of Normandy, but the US 5th Fleet boasted no fewer than 16 aircraft carriers and more than 900 combat aircraft. The attack group carried two divisions of Marines and one of Army infantry and the stakes of both invasions were similar. (NPR)

In June 1944, Admiral Raymond A Spruance’s 500-ship fleet, carrying about 125,000 Marines and Sailors steamed 1,000 miles from the Western Marshall Islands to the South Mariana Islands.   This fleet included most of the Navy’s carriers and battleships, along with many of its transports of the Pacific Fleet.

The Mariana Islands were the last bastion of Japan’s Central Pacific perimeter.  Their capture by American Forces severed the Japanese supply lines with the Caroline Islands territories further south and pushed the defense west to the Philippines while opening the Japanese homelands for aerial assaults.

Spruance’s Task Force 58 launched the first of many pre-invasion air sorties on June 11 on Japanese positions, airplanes, and ships.  Both fast and escort carriers participated in these attacks that lasted until the capture of Guam on August 10.  (Navy)

They set D-day for June 15, when Navy Sailors would deliver Marines and Soldiers to Saipan’s rugged, heavily fortified shores.  The Navy’s involvement bookended the operation: naval vessels and personnel ferried Marines and Soldiers to the beaches and then, after ground combat was over, took leading positions in the administration of the occupation.

Japanese resistance proved far greater than anticipated, not least of all because the latest intelligence reports had underestimated troop levels.

In reality, troop levels, in excess of 31,000 men, were as much as double the estimates. For at least a month, Japanese forces had been fortifying the island and bolstering its forces. Although US submarines had managed to sink most of the transports to Saipan from Manchuria, the majority of these troops survived to supplement a full 13,000 men to the 15,000 or so already on site.

“The [Japanese] are coming after us,” Spruance said, and they were bringing with them 28 destroyers, 5 battleships, 11 heavy cruisers, 2 light cruisers, and 9 carriers (5 fleet, 4 light) with somewhere near 500 aircraft total.

The resulting engagement – the Battle of the Philippine Sea of June 19-20 – resulted in a decisive US victory that nearly eliminated Japan’s ability to wage war in the air.

By June 30, the 27th Infantry Division had swept through the hills and then down the valley where it finally destroyed the enemy.  Following fighting on the island, the Americans suffered 26,000 casualties (5,000 of which were deaths). Yet the American victory was decisive.

Japan’s National Defense Zone, demarcated by a line that the Japanese had deemed essential to hold in the effort to stave off US invasion, had been blown open. Japan’s access to scarce resources in Southeast Asia was now compromised. 

The cost of this campaign was great: over 16,500 casualties, including almost 3,500 killed.  The Marine units suffered close to 13,000 casualties.

Although the price for victory was high, the seizure of Saipan was a highly significant step forward in the advance on the Japanese home islands.  The island became the first B-29 base in the Pacific.  The war had reached a new turning point.

Some highly-placed Japanese felt that their defeat on Saipan signified the beginning of the end of the Empire. (Marine Corps University) (Lots of information here is from US Army, Navy and Marines, Department of Defense, Eisenhower Library and British Imperial War Museums.)

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