On the 75th anniversary of the Battle of Britain, we go in hunt for the aircraft that saved a nation.

On 10 July 1940, the Luftwaffe swarmed through the blue summer sky towards England. Gardeners looked up from their plots in Kent and Sussex, disturbed from their planting by the distant drone. The German planes outnumbered the British more than two to one. The Führer’s orders were uncompromising – “to eliminate the English motherland as a base from which war can be continued and, if necessary, to occupy completely”. Yet few could imagine the fight that would soon play out, the bombs that would fall, the tangled fuselages and bloodied pilots who would soon twist and tumble from the sky.

The Battle of Britain had begun.

London girded itself for the arrival of German paratroopers. Sir Winston Churchill practised with a revolver and rifle on his range at his country house, Chequers, in case he had to defend himself. But his public expressions of defiance could not conceal the facts. His coalition government was two months old. The war ministry was so desperate for aluminum to build more planes that it was calling on people to donate their pots and pans. Faced with the magisterial force of the Third Reich, Britain seemed to be responding with an Ealing comedy. Mr Hermann Göring, commander-in-chief of the Luftwaffe, advised his crews that “within a short period you will wipe the British air force from the sky”. His prediction had the terrifying ring of truth.

The British needed a miracle and it came flashing out of the sunlight, darting from behind clouds, turning knots in the Luftwaffe pilots’ necks, ripping apart their planes with gunfire before vanishing like a gnat into the haze. The Spitfire. No plane before or since has so encapsulated a moment. Slight, nimble but with a devastating bite, it was David against the German Goliath, piloted by men who knew the odds of survival were stacked against them.

To fly a Spitfire, it was said, was more like strapping wings to one’s back than fighting with the controls jammed inside a cockpit. “It was like pulling on a pair of tight jeans,” said Pilot Officer James Goodson of 43 Squadron. “I used to smoke a cigar sometimes – against all rules and regulations – but if I dropped it, instead of groping around on the floor, I’d move the stick a fraction of an inch, the Spit would roll over and I’d catch the cigar as it came down from the floor. That was the kind of plane it was. Everybody had a love affair with it.”

The pilot and author Mr HE Bates wrote that the Spitfire pilot “is engaged in a dangerous, apparently wonderful and often fatal occupation. Like the bull fighter, he works to and often in line with death… The coastal pilot is invisible, far out at sea; the bomber pilot is invisible, far out in darkness. The Spitfire pilot flies in the sun, turning his plane like a silver fish many thousands of feet up and fascinates the world below.”

Seventy-five years since it flew to Britain’s rescue, it continues to fascinate. Collectors will pay up to £4m for one in mint condition. The search for the best of them persists, most recently in Myanmar, where dozens of Spitfires are rumoured to have been crated and buried at the end of WWII. If true, it would be an astonishing find, worth millions. The plane hunters, archaeologists and their financial backers have bickered in public, and Mr David Cundall, a Lincolnshire turf farmer who has spent nearly 20 years chasing down the story of the buried Spitfires, has been called a fantasist and a Walter Mitty character. “It’s not a myth,” insists Mr Cundall. “It’s true.” He still hopes to prove it.

Mr Leo McKinstry, the author of Spitfire: Portrait of a Legend, a history of the plane, calls it “an enriching symbol of national identity and freedom, a tiny, vulnerable but heroic creature that inspired fear in the world’s darkest tyranny”. But it is more than just a historical artefact. It is a coveted marvel of engineering; a plane so elegant, simple and devastatingly fit for purpose that it took down the greatest air force the world had ever seen.

Its creator was one of those quiet, mysterious Englishmen, all but lost to history, who had such bearing over events. Just as Mr Alan Turing’s success in cracking the Enigma code broke Germany’s naval efforts, so it was Mr Reginald Joseph “RJ” Mitchell’s Spitfire that saw off the Third Reich in the air.

Mr RJ Mitchell did not live to see his greatest creation win the Battle of Britain, let alone the 20,000 more Spitfires flown throughout the war, from the Siege of Malta to D-Day. He died in June 1937 of cancer. He was a largely self-taught engineer, who had grown up in Staffordshire and left school at 16 to work as an apprentice at a locomotive maker. As a boy, he had shown an aptitude for maths and drawing and used to make models of airplanes out of bamboo cane, paper and twisted rubber. At 21, he was hired by the aircraft maker Supermarine. In 1920, when he was just 25, he was appointed chief engineer and designer; a prodigious and rapid rise.

His boss, Sir Robert McLean, called Mr Mitchell a “curious mixture of dreams and common sense”. His office was a mess of tottering piles of paper and half-finished models. But hand him a rudder and he could accurately judge its weight just by holding it in his palm. He loathed formality and would always insist on sitting with his employees at company dinners. He could stare at his drawing board for hours, lost in concentration, applying what his test pilot, Mr Jeffrey Quill, called his “direct and shining common sense” to the problems of engineering and design. Mr Mitchell once admonished Mr Quill: “Jeffrey, if anyone tries to tell you something about an aeroplane which is so damned complicated that you can’t understand it, then you can take it from me that it’s all balls.”

In 1927, Mr Mitchell’s S5 Supermarine plane won the prestigious Schneider Trophy, an international seaplane race. The S5 zoomed across the lagoon in Venice at 281mph. His achievements caught the notice of the British government. When the Nazis began to rearm Germany, Mr Mitchell was given the brief of developing a new kind of fighter plane, one that could run rings around the Luftwaffe and be built in huge numbers.

Various names for it were considered, including Shrew and Snipe. Sir Robert settled on the nickname he used for his feisty young daughter Ann, a “right little spitfire”. The plain-spoken Mr Mitchell did not care for it: “Just the sort of bloody silly name they would think of.”

There was nothing “bloody silly” about his design, though. With its streamlined fuselage and cantilevered, elliptical wings, it was an extraordinary balance of lightness and power. The elliptical wing meant that if the plane stalled in mid-air, the pilot still had some control over it. When other designers gushed over it, Mr Mitchell replied: “I don’t give a bugger whether it’s elliptical or not, so long as it covers the guns.”

When Mr Quill took the Spitfire for an early test flight in the spring of 1936, he said that, as it soared higher and faster, it was “reminiscent of my old Bentley cruising in top gear” – smoother the quicker it went.

When war broke out, the British public was similarly enchanted. Lord Beaverbrook, the press baron whom Sir Winston appointed minister of aircraft production, sold the legend of the Spitfire as he would a scoop in The Daily Express. He organised Spitfire Funds, through which local communities donated enough to build 2,700 planes. The mystery writer Ms Dorothy L Sayers wrote, “A fighter plane is, comparatively speaking, a very small machine and there is something irresistibly endearing about a very small thing that fights like hell…When a ferocious giant has been coming at one with a club, the impulse to send the hat round for Jack the Giant Killer is too strong to be restrained by any calculations of policy.” Lord Beaverbrook asked the British to pay for these plucky planes and in doing so the British came to feel they owned them.

Mr Peter Arnold, a former Aston Martin engineer and British Spitfire enthusiast, who has visited every single surviving Spitfire in the world, describes it as “the biggest engine attached to the lightest airframe you could attach behind it”, designed so it could be easily and repeatedly updated. As a schoolboy, Mr Arnold used to cycle 50 or 60 miles in a day just for a look at a Spitfire parked on a distant runway. “We’d climb over barbed-wire fences on a Sunday afternoon to get the photograph,” he says of the fabled plane, its round nose pointing skyward as if sniffing for enemies no longer there. “It’s a bloody sexy-looking airplane.”

Two years ago, Mr Arnold travelled to Yangon, Myanmar, to witness the planned excavation of the rumoured cache of planes buried at the end of WWII. He admired Mr Cundall’s tenacity and, if he turned out to be right, Mr Arnold wanted to be there to see it. For lovers of military aircraft, this would be like the opening of King Tutankhamun’s tomb.

Until 1996, Mr Cundall had confined his archaeological adventures to airfields in Britain, where he would dig for old planes. But that year, he met a British veteran named Mr Stanley Coombe, who had served in Burma at the end of WWII. During the final days of the war, Mr Coombe claimed to have seen huge crates being buried underground at Mingaladon, now the location of Yangon International Airport. He was told by someone in the RAF that the crates contained Spitfires. They were being stored on the orders of Lord Mountbatten, the Supreme Allied Commander in Southeast Asia, as a gift to the Karen, one of Burma’s largest tribes, who had helped drive the Japanese out of the country and whose pilots had flown Spitfires alongside the British.

The tenacious Mr Cundall began to probe. In 1996, Myanmar was still largely closed to the outside world but he began to visit once or twice a year, pressing the government for help and information. He scoured the archives, interviewed witnesses who could corroborate Mr Coombe’s yarn, and came to believe there might be 36 Spitfires at Mingaladon and about another 18 at an airfield in Myktina in the north of the country. It was a cache potentially worth millions to whoever could get to it. Collectors and investors began to circle.

But Myanmar is not an abandoned airfield in Lincolnshire. The British ambassador in Myanmar warned Mr Cundall to stay away. The Karen had been fighting a civil war against the Burmese government for decades. Searching for the Spitfires risked stirring ghosts from the earliest years of Burmese independence, notably the assassination of General Aung San, the founder of modern Myanmar and father of the Nobel Peace Prize winner Ms Aung San Suu Kyi. In 1998, Aung San Suu Kyi was between long periods of house arrest for her opposition to the military government. It was still rumoured in Myanmar that the British had been involved in her father’s murder. The combination of the lingering conflict with the Karen and Western interest in nudging Myanmar towards greater political freedom meant it served little purpose to have Westerners digging for buried treasure. It was a “can of worms”, the ambassador said.

But Mr Cundall persisted and by 2013 Myanmar had begun to open up. He raised money from the online game maker Wargaming and led a team of archaeologists and geologists to Mingaladon airport. They set up camp on the edge of the runway at the spot where their geophysical surveys suggested lay Mr Cundall’s long-dreamed-of underground bunker, propped up by teak and concrete, containing greased and crated Spitfires. But just as they were about to start digging, security men ordered them to stop. The government was concerned that they would compromise the integrity of the runway by digging so close to it. A month later, permission was finally granted for the dig to commence, only for it to draw a total blank.

Mr Cundall was devastated, embarrassed in front of a large press corps who had gathered to watch his dig. Wargaming disowned him. His Spitfires, it said, were nothing more than a street myth.

The experience might have crushed anyone not so steeped in the legend of the Spitfire. It is hard to judge yet whether Mr Cundall has Mr Mitchell’s “curious mixture of dreams and common sense” or an optimism less grounded in reality. But he is still darting and twisting, raising money and hoping for another run at his dream. He says he has the support of Myanmar’s president and defence minister. The Transport Ministry, however, is still worried about the potential damage to its runway.

In the meantime, he believes he has found the site of the Dhammazedi Bell, a bronze bell said to be the largest ever cast, which used to hang in the Shwedagon Pagoda in Yangon. In the early 17th century, it was stolen by a Portuguese warlord but sank at the confluence of the Bago and Yangon rivers in southern Myanmar. Various groups have tried to locate and recover it. Whoever does and restores it to its place in the Shwedagon will have the eternal gratitude of Myanmar’s Buddhist leaders. It’s a long way round to the fabled store of Spitfires but Mr Cundall still trusts that vindication and a fortune awaits.

If you’re intrested in landing your own piece of Battle of Britain history, London auction house Christie’s is selling an authentic and immaculately restored Vickers Supermarine Spitfire Mk.1A – P9374/G-MK1A in The Exceptional Sale on 9 July to commemorate the 75th anniversary of the Battle of Britain.