The Longest Day is a book by Cornelius Ryan

Cornelius Ryan

Cornelius Ryan, was an Irish journalist and author mainly known for his writings on popular military history, especially his World War II books: The Longest Day: June 6, 1944 D-Day , The Last Battle , and A Bridge Too Far .-Early life:Ryan was born in Dublin and educated at Synge Street CBS,...

 published in 1959, telling the story of D-Day

D-Day

D-Day is a term often used in military parlance to denote the day on which a combat attack or operation is to be initiated. "D-Day" often represents a variable, designating the day upon which some significant event will occur or has occurred; see Military designation of days and hours for similar...

, the first day of the World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 invasion of Normandy. It includes details of Operation Deadstick

Operation Deadstick

Operation Deadstick was the codename for an airborne forces operation by the British Army that took place on 6 June 1944 as part of the Normandy landings. The mission's objective was to capture intact two road bridges in Normandy across the River Orne and the Caen Canal providing the only exit...

, the coup de main

Coup de main

A coup de main is a swift attack that relies on speed and surprise to accomplish its objectives in a single blow. The United States Department of Defense defines it as:The literal translation from French means a stroke or blow of the hand...

operation by gliderborne troops

Military glider

Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...

 to capture both Pegasus Bridge

Pegasus Bridge

Pegasus Bridge is a bascule bridge , built in 1934, that crossed the Caen Canal, between Caen and Ouistreham, in Normandy, France....

 and Horsa Bridge

Horsa Bridge

Horsa Bridge, also known as Ranville bridge, over the Orne River, was, with Pegasus Bridge, captured during Operation Deadstick by gliderborne troops of the 2nd Oxfordshire and Buckinghamshire Light Infantry in a coup de main operation in the opening minutes of D Day, 6 June 1944, before the main...

 before the main assault on the Normandy beaches. It sold tens of millions of copies in eighteen different languages.

The book is not a dry military history, but rather a story about people, and reads at times like a novel. It is based on interviews with a cross-section of participants, including U.S., British, French and German officers and civilians.

Researchers spent almost three years locating survivors of D-Day and over 700 interviews were undertaken in the United States, Canada, Great Britain, France and Germany. 383 accounts of D Day were used in the text of the book.

Senior Allied officers who assisted the author included General Maxwell D. Taylor

Maxwell D. Taylor

General Maxwell Davenport "Max" Taylor was an United States Army four star general and diplomat of the mid-20th century, who served as the fifth Chairman of the Joint Chiefs of Staff after having been appointed by the President of the United States John F...

, Lieutenant General James M. Gavin

James M. Gavin

James Maurice "Jumpin' Jim" Gavin was a prominent Lieutenant General in the United States Army during World War II...

, Lieutenant General Sir Frederick E. Morgan

Frederick E. Morgan

Lieutenant General Sir Frederick Edgeworth Morgan KCB was a British Army officer who fought in the First World War and the Second World War...

 and General Sir Richard Nelson Gale

Richard Nelson Gale

General Sir Richard Nelson "Windy" Gale GCB, KBE, DSO, MC was a soldier in the British Army who served in both world wars. In World War I he was awarded the Military Cross in 1918 whilst serving as a junior officer in the Machine Gun Corps...

.

German officers who assisted with the book included Colonel General Franz Halder

Franz Halder

Franz Halder was a German General and the head of the Army General Staff from 1938 until September, 1942, when he was dismissed after frequent disagreements with Adolf Hitler.-Early life:...

, Captain Hellmuth Lang and Major General Gunther Blumentritt

Günther Blumentritt

Günther Blumentritt was a German officer in World War I, who became a Staff Officer under the Weimar Republic and went on to serve as a general for Nazi Germany during World War II...

.

The author also used Allied and German post action reports, War diaries, histories and official records.

On 6 June, 1965, the author published an article "More of The Longest Day" on Reader's Digest as a supplement.

Cornelius Ryan dedicated his book for all the men of D Day.

The book takes its name from a quote by Erwin Rommel

Erwin Rommel

Erwin Johannes Eugen Rommel , popularly known as the Desert Fox , was a German Field Marshal of World War II. He won the respect of both his own troops and the enemies he fought....

: "...the first 24 hours of the invasion will be decisive...the fate of Germany depends on the outcome...for the Allies, as well as Germany, it will be the longest day."

The Longest Day

The Longest Day (film)

The Longest Day is a 1962 war film based on the 1959 history book The Longest Day by Cornelius Ryan, about "D-Day", the Normandy landings on 6 June 1944, during World War II....

is also the name of a 1962 film based on the book, featuring many star actors.