It is estimated between a quarter and half of the world's population has seen a James Bond film. That number will likely rise even higher when Spectre – the 24th film in the franchise – is released globally on 6 November.

But of the 15 real secret agents that allegedly provided the basis for Ian Fleming’s super suave spy – few know about Sir William Samuel Stephenson, whose hand-to-hand combat skills, save-the-world heroics, magnetic personality and predilection for martinis remarkably mirror those of 007. In fact, Stephenson isn’t even recognised in his hometown: Winnipeg, Canada.

Of the 15 secret agents that provided the basis for James Bond – few know about Sir William Samuel Stephenson

“In all my years in this job you're only the second person who asked about Stephenson,” said Don Finkbeiner, owner of Heartland Tours. “His story even catches most Winnipeggers off guard even though many of them drive past his statue every day.”

To become an ultimate spymaster, marry an American heiress?

A WWI fighter pilot and lightweight boxing champion in the forces, Stephenson relocated to the UK after the war ended in 1918. There, he married an American tobacco heiress and used her connections to reinvent himself as the ultimate spymaster during WWII, becoming a close confidant to both Winston Churchill and Franklin Roosevelt and playing a key role in the establishment of the CIA. He also founded Camp X, a commando-training base near Toronto where Fleming and hundreds of other Allied operatives learned their craft during the war.

His story is incredible. It's almost too good to be true.

“I myself only learned about Stephenson 10 years ago and now I incorporate a visit to his statue on all my tours,” Finkbeiner said, walking me past the large bronze statue of the pilot that stands in front of the Manitoba Legislative Building. (An identical statue is at CIA headquarters in Langley, Virginia.) “I tell people: you're about to meet the most important Winnipegger of all time and probably the most important Canadian period. His story is incredible. It's almost too good to be true.”

Stephenson was raised in the neighbourhood of Point Douglas in a humble two-story wooden house. He lived there and attended the Argyle Alternative High School until he enlisted in the army at the age of 16. A mural on the school’s wall incorporates the spy’s likeness – but other than that, there’s little evidence that Stephenson grew up there. Either the neighbourhood forgot, or like any good spy, Stephenson wanted to be forgotten.

Either the neighbourhood forgot, or like any good spy, Stephenson wanted to be forgotten.

A more descriptive mural in Winnipeg’s West End paints a better picture of Stephenson’s achievements. Most notably, it includes an image of the Wehrmacht Enigma, the seemingly unbreakable Nazi code machine that Stephenson helped break.

“Stephenson was a tech guru and wildly successful in business,” Finkbeiner said. “He patented a way of sending photographs through wireless telegraph. He also got into the steel industry, the automobile industry, aviation – he helped develop the Spitfire – and was one of the first directors [of public relations] for the BBC.”

Stephenson is also credited with providing intel for the 1943 sabotage of the Vemork Hydroelectric Plant in Nazi-occupied Norway. Known as Operation Gunnerside, the mission prevented Nazi scientists from getting their hands on the heavy water needed to produce a hydrogen bomb that otherwise may have altered the outcome of WWII. The operation is recognised as the Allies' most successful act of sabotage during the war.

“As an individual, Stephenson ranks next to Churchill and Roosevelt in his persistent efforts to defeat the Germans,” said Gary Solar, secretary of The Intrepid Society, a group dedicated to maintaining the memory and raising the profile of Winnipeg’s most intrepid son. “There are so many things he did to reduce the length of the war and loss of human life.”

To help memorialize Stephenson’s good work, Solar and society president Kristin Stefansson worked to rename Winnipeg’s Water Avenue as William Stephenson Way in 2009. Solar and Stefansson are also both descendants of the man whose code name was Intrepid – yet neither of them, Solar joked, were mentioned in his will.

Where Bond is fictional, Stephenson is a real, true spy

Stefansson and Solar drove me to the McGregor Armory where Stephenson joined the 101st Battalion of the Winnipeg Light Infantry in 1914. His regimental number? 700758. No evidence exists to show Fleming made the connection when he concocted Bond's iconic 007 designation, yet the similarity is intriguing. The same can be said of the plot of Goldfinger, Fleming's seventh Bond novel, published in 1959. The evil mastermind's fictional raid of Fort Knox is analogous to Stephenson's unrealised plot to steal nearly $3 billion of Vichy gold reserves from the French colony of Martinique.

Next we headed to the Billy Bishop Building at Winnipeg's 17 Wing air base to see a permanent exhibition of more than 300 Stephenson artefacts curated by The Intrepid Society. It includes letters from J Edgar Hoover and Ronald Reagan, an oil painting of the man called Intrepid, and medals Stephenson was awarded by the US, the British, French and Canadian Governments. The guards refused my entry into the base after I identified myself as a journalist, but civilians are granted access anytime between 9am and 5pm on weekdays.

James Bond is a highly romanticised version of a true spy, Fleming wrote. The real thing ... is William Stephenson.

The Sir William Stephenson Library in North Winnipeg has a smaller number of Intrepid artefacts enclosed in a glass cabinet. Alongside a model of a Sopwith Camel biplane, which Stephenson used to down 12 WWI enemy aircraft (including that of Lothar von Richthofen, the younger brother of the Red Baron), there are half a dozen biographies on Stephenson.

Solar removed one of the books, Room 3603 by H Montgomery Hyde and pointed to the preface, written by Fleming himself. In it, are two very telling statements.

The first: Fleming describes how Stephenson “used to make the most powerful martinis in America and serve them in quart glasses”, providing insight into how the author came up with the idea for Bond's iconic tipple.

The second, at the end of the preface, is the clincher – proof that Stephenson, who died in Bermuda in 1989, was integral to the creation of the fictional secret agent at the centre of the most enduring movie franchise in history.

“James Bond is a highly romanticised version of a true spy,” Fleming wrote. “The real thing ... is William Stephenson.”