It became known as the "Summit Series" and what transpired over 27 days in September 1972 inspired at least half a dozen books, a television miniseries or two, and even a country music ballad.

The series was described as "the biggest athletic engagement in Canada’s history" by Tim Burke, a writer for the Montreal Gazette newspaper. 

Ice hockey was then vitally important in the Canadian sporting psyche and remains so to this day.

Canada had won the first Olympic ice hockey gold medal in 1920 and had largely dominated Olympics and World Championship before the second world war. 

The Russians had absented themselves from international sport, but in the 1940s and 1950s, they became prominent in a range of events.

They won the 1954 world title and although Canada won the 1955 Championship, represented by the Penticton Vees from British Columbia, the wind of change was apparent.

At the 1956 Winter Olympics, the Soviets took ice hockey gold at the first attempt.

They also won the World Championship in every year from 1963 to 1971 and became known as the "Red Machine".

The best Soviet players were considered amateurs, though many trained full time and it was reported in the West that they were rewarded well for their efforts.

Sport between East and West was still a matter of political prestige, but cold war politics had started to give way to detente and sporting contact was the pathway chosen.

In 1971, Canada’s Prime Minister Pierre Trudeau travelled to the Soviet Union for the first time.

When Russian Premier Alexei Kosygin made a reciprocal visit, he received a mostly hostile reaction, except during a visit to the National Hockey League (NHL) match between the Vancouver Canucks and the Montreal Canadiens.

Spectators displayed banners with the message "Welcome Premier Kosygin", and gave a standing ovation.

Kosygin presented souvenirs to Canadiens captain Henri Richard and Canucks skipper Orland Kurtenbach.

"I have a pair of skates at home, but I'm too old to use them now," Kosygin joked through an interpreter.

"This is a great game and it should be played internationally between our countries," he told Canucks general manager Bud Poile.

"The light went on for Kosygin that October night in Vancouver," wrote Canadian diplomat Gary Smith in his book Ice War Diplomat, which tells the story of the Summit Series.

"If the Soviet Union wished to improve its relationship with Canada and enhance cooperation, the way to do it was through hockey," Smith added.

By the early 1970s, Canada was effectively boycotting the Olympic and World Championship tournaments because the best Canadian players, professionals in the NHL were barred from competing.

This also frustrated the Soviets who had consistently beaten everyone, but were denied the ultimate challenge of facing off against the very best Canadian players.

So a few weeks after Kosygin’s visit, Smith, a fluent Russian speaker attached to the Canadian embassy in Moscow, was intrigued by an article by the sports editor Boris Fedorov, which appeared in the Russian newspaper Izvestia.

This called for an ice hockey showdown between the Soviets and the Canadians.

After months of talks, a Canadian negotiating team travelled to Prague to finalise arrangements for the series at the congress of the International Ice Hockey Federation.

"The Soviets agreed to play an eight-game series, their best against ours, no strings attached," an official Hockey Canada report stated. 

Although billed as an exhibition, there was no denying the strong political undercurrent to the series.

The Canadians decided to choose their squad exclusively from players in the NHL, a policy that excluded stars including Bobby Hull, who had signed for the newly formed World Hockey League.

The squad was assembled with the help of Alan Eagleson, a lawyer who led the NHL Players' Association.

Described in the Toronto Globe and Mail as "manager and motivator, travel agent and godfather, firebrand and peacemaker", Eagleson was later ostracised by many in the game after he was prosecuted for financial irregularities. 

The team was coached by Boston Bruins' Stanley Cup winning coach, Harry Sinden, an Olympic silver medallist as a player in 1960.

The 21 forwards he named had scored 736 goals in the previous season.

The goaltenders had recorded 19 shut outs that so many in Canada were confident of an emphatic victory as the team warmed up with intrasquad exhibition matches.

The Soviets were coached by Vselvolod Bobrov, who had won Olympic gold as a player in 1956.

His side flew into Montreal on Aeroflot flight 301 three days before the series began.

They were taken to see "The Godfather" starring Marlon Brando.

"We understand there is a lot of action and the language barrier won’t be as serious as if we had to follow a melodrama or comedy," Bobrov explained.

Canadian newspapers were fascinated by every last scrap of information about their exotic visitors.

The Queen Elizabeth hotel in Montreal even revealed that the appetite of Soviet players "exceeded anything we have seen amongst athletes yet". 

The first match was at the Montreal Forum where Prime Minister Trudeau was presented to the teams.

After national anthems, played on the arena’s organ, he stepped forward to drop the puck for the ceremonial face off.

"The politburo asked us to guarantee a good result," Soviet keeper Vladislav Tretiak admitted later in a television documentary.

"This was for the prestige of the country, we were the Olympic champions."

The optimism of many Canadians seemed well founded when Phil Esposito scored after only 30 seconds of play although a second goal soon came, the Soviets rallied to equalise and eventually drew away to win 7-3.

"We were stunned, it wasn’t so much that the Soviets won but the way they won with speed, finesse, outstanding goaltending and teamwork," Sinden admitted afterwards.

The Canadians struck back with a 4-1 victory in the second match but the third was drawn 4-4.

The Soviets won the last encounter on Canadian ice by 5-3.

This prompted some Canadian fans to boo their team and provoked an emotional response from Phil Esposito in his interview with television presenter Johnny Esaw.

"For the people across Canada, we tried, we did our best," Esposito began.

"For the people that boo us, all of us guys are really disheartened and disillusioned, we’re disappointed in some of the people, we cannot believe the bad press we’ve got.

"Everyone of us came out and played because we love our country, we did it for no other reason."

Before the series resumed in Moscow, the Canadians played matches in Sweden to acclimatise to European conditions.

"You don’t win at hockey unless you are a team, we weren’t a team when we played the four games in Canada," Esposito reflected years later in a half-time interview for Canucks TV.

"We became a team in Sweden, when it seemed like everybody was against us, sometimes you rally around things like that and that’s what we did."

The turnaround did not come immediately.

In game five, the Canadians led 4-1 and seemed well on the way to victory on their first appearance in Moscow, but the Soviets stormed back to win 5-4.

"They play the game as though there were no scoreboard," an admiring Sinden reflected.

"We don't have a team in the NHL that would have played the way they did in the final ten minutes."

The Canadians won 3-2 in game six but were criticised for rough play.

"The Soviet hockey fans were friendly toward the Canadian guests, but they were disappointed by the tough methods of some Canadian professionals," Soviet state newspaper Pravda reported.

The Canadians also won Game seven in another tightly fought match, this time by 4-3.

Before the final deciding match, Hockey Canada President Charles Hay presented a traditional totem pole to his hosts.

The Soviet players were each presented with a stetson and then the match began.

It swung one way and then the other.

As the final period began, the Soviets were leading 5-3, but the Canadians scored twice to level.

Then with only 34 seconds left came the decisive goal from Paul Henderson to provoke rejoicing across Canada.

A total of 25,000, including Prime Minister Trudeau, waited to greet them when they returned to Montreal.

A further 50,000 were present in Toronto to welcome team members.

Meanwhile in Moscow, Pravda suggested that "the deep-seated myth about the invincibility of the hockey founders was destroyed".

"Obviously our team is lacking in physical training in comparison with our rivals, we should mention that the game of professionals was marked with serious defects that are foreign to the real sport," it continued.

"The total score of all eight matches is 32:31 in favour of the Soviet team, however, figures are not so important in these games."

The final verdict was recorded by Hockey Canada.

"After the most exhilarating 480 minutes of hockey anyone can remember, Canadians would have learned far more than whether we were still the world’s greatest players, we would have learned humility and we would have lost our complacency."