Gen. Montgomery wrote his entire D-Day invasion plan on a single piece of paper - here it is

AP

Gen. Bernard "Monty" Montgomery addresses British troops

• The invasion of Normandy, France on D-Day was a massive and complex military operation involving hundreds of thousands of military personnel.
• Allied war planners spent months preparing for the assault, drafting up numerous plans for the spearhead into German-occupied western Europe.
• One commanding general, Britain's Gen. Bernard Montgomery, kept it simple, scribbling out his plans for the largest land, air and sea operation in military history on a single sheet of paper.
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The Allied invasion of Normandy on D-Day was one of the most complex military operations ever undertaken, but amid the intense preparation and planning for history's largest combined land, air, and sea operation, one commanding general kept it simple, scribbling out his war plans on a single piece of paper.

Around 160,000 Allied troops, supported by thousands of ships and aircraft, either parachuted into France or stormed its beaches beginning on June 6, 1944. Allied war planners spent months planning the invasion, the beginning of the Allied spearhead into German-occupied Europe known as Operation Overlord.

Read more: D-Day by the numbers: Here's what it took 75 years ago to pull off the biggest amphibious invasion in history

British Gen. Bernard "Monty" Montgomery served as a ground commander for Anglo-American forces under Supreme Allied Commander Gen. Dwight D. Eisenhower.

His penciled battle plan for D-Day took up no more than one piece of paper and included a note that read: "The key note of everything to be SIMPLICITY."

Imperial War Museums

Montgomery's plans for D-Day

Montgomery's plans, which were labeled "Most Secret," were released for the first time in 2016 by the Imperial War Museums for the 72nd anniversary of the invasion.

The museum also released a handwritten draft of the general's speech to Allied troops, which officers read aloud to the invading forces just before the assault began.

"The time has come to deal the enemy a terrific blow in Western Europe," the speech read. "The blow will be struck by the combined sea, land and air forces of the Allies."

"Good luck to each one of you," Montgomery concluded his message. "And good hunting on the mainland of Europe."