Brutal ends that justified the means during the very first SAS mission against the Nazis

The Italian and German pilots sat playing cards and drinking beer in the Nissen hut, the air thick with cigarette smoke and the sound of raucous laughter. Many had only recently arrived at Tamet airbase, having moved their warplanes from Sirte, some 30 miles to the east. Earlier a convoy of British raiders had been spotted moving through the Libyan desert. Fearing they were on their way to attack, the order was given to evacuate all aircraft and their crews to Tamet.

Believing they had escaped the raiders' clutches, the pilots were enjoying themselves, but not for long... Suddenly, the door flew open. The laughter stopped. The conversation stilled. All heads turned to see who had made such an abrupt entry. Standing there silhouetted in the doorway were three men, bearded and with long, unkempt hair, making a peculiar and frightening sight.

All were armed, one brandishing a distinctive Tommy Gun. One figure towered over the rest, being well over six feet tall. He began to speak, in a soft, lilting Ulster brogue: "Good evening, gentlemen."

Before any of the pilots had a chance to react, all hell let loose. The British raiders opened up, the Tommy gun spitting out deadly fire. Again and again, they raked the room with bursts, as bloodcurdling screams and gasps rent the air. Soon the hut was littered with dead and dying men.

Their deadly work done, the trio melted away into the night, but not before "shooting out the lights, and hurling a volley of grenades to add to the confusion". The Special Air Service had just executed its first raid.

One of the standout soldiers of the Second World War had led that blistering attack, someone who would go on to become the most highly decorated British Army soldier. Blair 'Paddy' Mayne had scored first blood for the SAS. Killing enemy aircrew in cold blood might appear savage, but this was a 'total war', one waged to save the civilised world from the perils of Nazism.

Winston Churchill had decreed that no enemy soldier should be able to sleep soundly in his bed at night, urging his raiders to leave a trail of enemy corpses in their wake. And as Mayne appreciated, it took far longer to train a pilot than to build an aircraft. Aiming to hamstring the enemy's airpower, killing pilots was amongst the most effective ways to do so. The ends justified the means.

The piratical raiders stole away into the darkness, seeking out warplanes for the incendiary bombs that they carried. As confusion reigned, the SAS went about their deadly work, before slipping into the night as quickly as they'd appeared. At their backs a series of explosions rent the night, as 24 enemy aircraft were ripped apart.

With those planes burning fiercely, the enemy was left to wonder just who it was that had attacked them. The commander of Tamet airbase feared a force of hundreds of British commandos had landed via the sea, complete with RAF warplanes in support.

Convinced his airbase was about to fall, he radioed for reinforcements. In truth, the attacking force consisted of Mayne plus half a dozen men, moving on foot and planting their lightweight Lewes incendiary bombs. Yet no one on the enemy side could conceive the raiders had come from the open desert and might disappear the same way.

The war in North Africa hung in the balance, as the British pushed west from Egypt, before the Germans hit back again, forcing them to retreat. This 'back and forth' was due to the age-old problem with such warfare - maintaining supply lines. The vast expanses of the Sahara lay to the south, forcing the war to be played out along the narrow northern strip.

All along the coastal plain there ran a surfaced road, which served as Rommel's key supply line. It was the route to ferry war materiel from the coastal ports to the frontline troops.

Something radical had been needed to end this stalemate, turning the tide in the Allies' favour. It was David Stirling, a young Scots Guards officer, who'd had the idea of forming a small band of elite warriors to attack airfields and supply columns, striking from out of the desert wastes, from where Axis forces least expected it.

General Claude Auchinleck, the overall British commander in North Africa, had given Stirling an enthusiastic go-ahead for such high-risk, high reward operations. Years later, Stirling described his vision as "a new type of force, to extract the very maximum out of surprise and guile".

Recruiting officers such as Blair Paddy Mayne, Bill Fraser and Jock Lewes, they handpicked men who had the same attributes and outlook on how to wage unconventional warfare. But the SAS's first mission, Operation Squatter, had ended in disaster. Parachuting into a freak desert storm, many were killed, leaving only a handful of survivors. With that failure, the prospect of the SAS being disbanded was very real.

A chance remark by David Lloyd Owen, an officer with the Long Range Desert Group (LRDG), the desert reconnaissance specialists, was to change everything. Rather than go in by air, he suggested the LRDG should drive the SAS to their targets. They had extensive experience of navigating the harsh desert terrain. Stirling readily agreed and so a legendary partnership was born.

The Tamet raid was the first such collaboration, and it had proven that this style of warfare could pay dividends. The SAS had struck a series of blows deep behind the lines, and it had taken just a handful of men. Then Stirling and Mayne had another idea that epitomised the spirit of thinking the unthinkable, and then putting it into action.

Their next mission should be a repeat of the first. Not only would they return to Tamet, but they would do so between Christmas 1941 and New Year, during the season of goodwill to all. As it was unthinkable, so it should be completely unexpected by the enemy. The element of surprise would be complete.

On December 27, Mayne's raiders returned to the place where they had caused so much devastation just a few weeks earlier. Again, a handful of men moving on foot found a way through and, for the second time in a month, the warplanes at Tamet were blown to pieces, this time the tally being 27. As the ranks of the SAS swelled, so too did their legend, as each new raid dealt a hammer blow to the German war machine.

Trained hard, each candidate had to be of a certain calibre; super-fit, able to think laterally and to excel under pressure. This was a meritocracy, rank of no real importance. Each man needed the right attitude and mindset to operate deep behind the lines, often for weeks on end. Anyone not up to the task was returned to their parent unit. By the spring of 1942, the SAS had added heavily-armed and nimble Willys jeep to their arsenal.

Fitted with Vickers K machine-guns, cannibalised from obsolete aircraft, they could handle the harsh desert terrain, while putting down a fearsome rate of fire. Their effectiveness was to be proven during the audacious attack on the Sidi-Haneish Airbase in July 1942. Sidi-Haneish was the key staging post for new warplanes - those freshly arrived in theatre.

Intelligence reports suggested it was packed with Ju52s, transport aircraft Rommel relied upon to keep supplies flowing to his foremost positions. Stirling thought it the perfect target for such an attack. Roaring out of the night, the jeeps smashed through the perimeter fence and raced up the runway, as the Vickers machine-guns blasted at the rows of enemy planes to either side.

Spurts of tracer groped for their targets, and moments later the airframes glowed red, before fire ripped through the fuselage, a dragon's breath of hot air belching over the nearest vehicles.

Rows of Ju52s, Dorniers and Stuka dive-bombers burst into flames. In a matter of seconds, the airbase was transformed into utter confusion, chaos and bloody mayhem. With scores of planes burning and the enemy in disarray, Stirling gave the order to pull out. Once again the SAS had struck far behind the lines, leaving a trail of death and destruction in their wake.

With each new success, the SAS became an ever greater thorn in Rommel's side. Unbeknown to them, the German general had charged his troops to hunt down Stirling's commandos. He'd even formed a specialist unit to do so, which had trained with captured Willys jeeps, to better assess the SAS's capabilities.

But nailing the SAS would be no mean feat. By this time, the summer of 1942, they were masters of "shoot and scoot" attacks. They could strike anywhere at any moment, and with extreme violence, melting away just as quickly, to leave behind utter devastation and an enemy stricken with fear.

By the spring of 1943, following the Operation Torch amphibious landings in Tunisia and Algeria, the war in North Africa was drawing to a close. Rommel's Afrika Korps were being pressed from both east and west, the SAS keeping up a relentless assault on their supply lines. Facing defeat, the remnants of Rommel's forces were evacuated across the Mediterranean to Europe.

After three years of bitter fighting, Britain and her Allies had won. The SAS's contribution to the victory in North Africa was significant. Their hit and run operations dealt a major blow, not only to Axis supply lines and air power but also to their morale. No matter how deep behind the lines, no enemy soldier could sleep easy.

Rommel was to say of the SAS, they "had caused us more damage than any other British unit of equal strength". In truth, in terms of enemy warplanes destroyed, the SAS had caused the Axis in North Africa far greater harm than many units of far greater strength. Incredibly, they had accounted for 367 confirmed aircraft 'kills', and very possibly as many as 400; arguably, more than the Royal Air Force had accounted for in North Africa during the same period.

With the war there won, the SAS turned their attention further north, as Allied commanders prepared to crowbar open Fascist and Nazi occupied Europe. Focusing on Sicily and Italy, they would attack "the soft underbelly of Europe", as Churchill described it. There, the legend of the SAS was to grow still further.

• Damien Lewis is author of several bestselling books about the SAS, including SAS Brothers In Arms (Quercus, £10.99)