“You must conceal 150,000 men with a thousand guns and a thousand tanks, on a plain as flat and as hard as a billiard table, and the Germans must not know anything about it, although they will be watching every movement, listening for every noise, charting every track.”

By Robert Hutton

IN OTHER circumstances, it would have been delightful. Colonel Dudley Clarke finished his meeting, walked across the Egyptian sand, stripped and then plunged into the cool blue water of the Mediterranean for a pre-lunch swim. It was 1942, and trunks weren’t British Army issue, so the officers at the headquarters of the Eighth Army swam naked. The prime minister, Winston Churchill, had recently joined them in this, to general delight.

But Clarke had heavy matters on his mind as he enjoyed the water. He’d just been briefed on the situation facing the British forces, and their plan to deal with it. A lot of men were going to die in a few weeks, and if he didn’t do his job right, there was a terrible danger that most of them would be on his own side.

And the problem was that his job was to deliver the impossible. It was set out by one of the men Clarke was meeting: “You must conceal 150,000 men with a thousand guns and a thousand tanks, on a plain as flat and as hard as a billiard table, and the Germans must not know anything about it, although they will be watching every movement, listening for every noise, charting every track.”

For two years, Allied and Axis forces had been chasing each other back and forth across the North African desert. At moments, each side had seemed to be poised for victory, only for it to be snatched away. Most recently, the German commander Erwin Rommel had believed he was on the brink of capturing Cairo, but had run out of momentum 150 miles short, where his army now sat.

They had been held there, south of the town of El Alamein, by exhausted, desperate forces drawn from across the British Empire. Although the desert was huge, in this part of Egypt only a relatively narrow strip of it next to the sea was suitable for vehicles. The two armies now faced each other along a front barely 40 miles wide. Rommel had failed to break through and was waiting for a counterattack from the new British commander, Bernard Montgomery.

While the British had built up their strength, with fresh troops and American tanks, the Germans and Italians had been fortifying. Up to this point, much of the war had been mobile, with Hitler’s armies making sweeping advances across Europe and the Soviet Union. What Montgomery now faced looked much more like the static lines of the First World War’s Western Front. He’d been injured in that war as a young officer, shot in the chest, and was determined not to repeat the mistakes and waste of life of that conflict.

But what could Montgomery do? Bounded by the Mediterranean to the north, and the Qattara Depression, impassable to tanks, to the south, he had no choice but to make a frontal assault. He needed a miracle. Which was why he had summoned Clarke to his headquarters.

Small, with a smooth oval face and a receding hairline, the 43-year-old Clarke was one of the Army’s best-kept secrets. For more than two years, he had been running a covert unit in Cairo with the mysterious, and glamorous, name of A Force. Its job was deception.

Deceiving one’s enemy in war was hardly a novel idea. Generals have been trying to mislead their opponents since the Trojan Horse. But Clarke had taken it to a new level. By this stage in 1942 he had developed an entire theory of the subject and put it into practice. Using a mix of double agents, faked documents, false wireless traffic and dummies built from wood and canvas, he had already persuaded German intelligence that Allied forces in North Africa were at least a third stronger than they really were. He could use fake units to make lightly-defended positions look stronger, deterring attack or  to threaten enemy-held areas, forcing the Germans to redeploy forces away from other parts of the front. In the years to come, people trained by Clarke would use his methods to deceive the Germans about the location of the D-Day landings, an undertaking known as Operation Fortitude. But on this day in 1942 Monty, as the British soldiers called their commander, wanted to see what Clarke could do to help him.

The general’s plan was simple enough. He wanted to launch simultaneous attacks at the northern and southern ends of the front. The southern attack would be a feint, designed to hold enemy forces there while the main thrust in the north would break through the German line then make a stand drawing Rommel’s tanks into a fight. He was going to attack at night, to give his men the greatest chance of clearing the minefields and getting past the guns that covered the front. They would need a full moon to see what they were doing. Conditions would be right in six weeks: on October 23.

There was a catch, however: Rommel could read a map. The German commander knew that the only road through the desert was in the north. What’s more, the Desert Fox had only recently launched an attack using a full moon. In effect, the British plan was to strike using an obvious route on a predictable day. As one of Monty’s aides said, it was all “horribly obvious.”

Clarke pondered the problem. After his swim, he had lunch with Montgomery and offered some thoughts. Any deception to mask the British plan would need to fool the enemy about the time of an attack and its location.

Clarke’s monumental task began with a simple misdirection. He hoped to give the Germans the idea that the British were less worried about North Africa and far more concerned that Hitler’s assault on Stalingrad might ultimately threaten the Persian Gulf and so were sending troops from North Africa to shore up the defences in the region. He also knew, too, that the Nazis felt vulnerable on the island of Crete, which they’d captured the previous year. Clarke also wanted to create the impression that this might be where the British were also focusing their attention. And a good sign that no attack was imminent along the front in Egypt would be the absence of the British generals from their headquarters. He would leak details of a sham conference for them in Iran for October 26.

Clarke could be sure that all of this intelligence would make its way back to the Germans. That’s because Berlin’s Nazi-friendly local spy network in Cairo was actually an entirely fictional creation by British intelligence. Double agents radioed in daily reports written by Clarke’s team.

Of course, none of these deceptions would make any difference if Rommel could see British troops moving up to the front. Both sides were flying reconnaissance planes, watching the enemy. The kind of attack Montgomery was proposing involved an awful lot of men and equipment. And the desert offered very little in the way of concealment.

Fortunately, for the Allies, Clarke was an unusual soldier, a maverick who often seemed to be on the verge of subordination. Yet he was appreciated by his commanders for his efficiency and his original approach to problems. He was also a born showman who imagined that his job was to put on an epic performance for the enemy, with the entire Middle East as his stage. Interestingly, Clarke’s uncle had been one of England’s leading amateur magicians, and no one knows more about deceiving an audience than an illusionist.

One of the men Clarke worked with was a camouflage expert named Geoffrey Barkas. For months, the 46-year-old former filmmaker had been arguing that his team could make a real difference to the war, and now he was going to get his chance to prove it. In the weeks that followed, Clarke and Barkas were going to pull off the biggest magic trick in history.

First, they had to set the stage. The British were going to need supplies for their performance, lots of them, everything from gasoline to powdered milk. One of Barkas’s men noticed that there were dozens of British slit trenches near the front that had been dug the previous year. From the air, these positions were clearly visible to German observation planes: clean lines in the sand crossed with dark shadows cast by the troops manning them. He experimented with stacking gas cans along the walls of the empty trenches so that they were invisible from the air.

Similarly, over a four-night period, a work party of 80 Australian infantrymen stacked boxes in the shape of army three-ton trucks, and then covered them with camouflage netting. From the air, it appeared there were a lot of trucks scattered about the desert. To the Germans, it looked fairly benign. Meanwhile, the real trucks were being marshalled for the coming attack.

This was only part of the trick, however. While men and material were being drawn together in the north, efforts were made to fool the Germans into thinking that the British were deploying for action in the south. That’s where yet another team was building fake supply dumps out of army beds turned on their sides and sackcloth. What’s more, work details put on an elaborate show of very slowly building a water pipeline that snaked towards the southern end of the front, ostensibly for an army gathering in the desert for an attack. In mid-October the pipeline clearly was barely halfway there. The implication was obvious: The British were planning something in the south, but their preparations were far from complete. Rommel was so confident that an attack wasn’t coming that he returned to Europe to see Hitler and then rest in the Austrian mountains.

But the greatest illusion was only just beginning. Over a series of nights beginning on October 18, the tanks that were going to be used in the attack advanced to their staging areas in the north. When they got there, they found a very special kind of magic prop waiting. Designed by Jasper Maskelyne, a famous British magician, it was a canvas and wooden disguise that made a tank look like a truck, at least from a distance. The camouflage was codenamed the Sunshield, and Barkas’s team had made hundreds of them. Engineers followed behind the disguised tanks as they moved using equipment to wipe away their telltale tracks. Meanwhile, dummy tanks were set up in the places where the real tanks had been. Each morning, when the sun came up, it looked to German observers as though nothing had changed. By the morning of October 23, Montgomery had an army massed and ready to attack. And remarkably, the enemy didn’t suspect a thing. German reconnaissance planes returned to base all week with the same message: “Nothing to report.”

That night, just before 10 p.m., the British guns opened fire. The next morning the Germans were still trying to understand what was happening. Rommel wasn’t back in his headquarters until October 25. It wasn’t until the following day that he ordered his panzer reserves to move north.

There was more than a week of brutal fighting ahead at El Alamein, as the Allied forces pushed their way through the line of dug-in defenders. The battle would be won, as they always are, by soldiers, not spies. But thanks to Clarke and his deceivers, Montgomery had achieved surprise.

Robert Hutton is the author of The Illusionist: The True Story of The Man Who Fooled Hitler, published by Pegasus Books. He is host of the podcast War Movie Theatre.