The Summit Series, Super Series 72, Canada–USSR Series (), or Series of the Century (), was an eight-game ice hockey series between the Soviet Union and Canada, held in September 1972. It was the first competition between the Soviet national team and a Canadian team represented by professional players of the National Hockey League (NHL), known as Team Canada. It was the first international ice hockey competition for Canada after they had withdrawn from such competitions in a dispute with the International Ice Hockey Federation (IIHF). The series was organized with the intention to create a true best-against-best competition in the sport of ice hockey. The Soviets had become the dominant team in international competitions, in which the Canadian professionals were ineligible to play. Canada had had a long history of dominance of the sport prior to the Soviets' rise.

The first four games of the series were held in Canada and the final four in Moscow. The Soviet Union surprised the Canadian team and most of the Canadian hockey media with an opening game victory, 7–3. Many Canadian sportswriters had predicted an overwhelming victory for Canada in the series. Canada won the next game 4–1; the third game was a tie. Canada lost the fourth game in Vancouver. The series resumed two weeks later in Moscow. The Soviets won the fifth game to take a two-game lead. The Canadians then won the final three games in Moscow to win the series four games to three, with one tie. The final game was won in dramatic fashion, with the Canadians overcoming a two-goal Soviet lead after two periods. The Canadians scored three times in the third, the final goal with 34 seconds left by Paul Henderson.

The series was played during the Cold War, and intense feelings of nationalism were aroused in fans in both Canada and the Soviet Union and players on the ice. The games introduced several talented Soviet players to North America, such as Hockey Hall of Fame inductees Alexander Yakushev, Valeri Kharlamov and goaltender Vladislav Tretiak. Team Canada, the first NHL and professional all-star team formed for international play, was led by Phil Esposito, who led the series in scoring, as well as contributing in other roles. The Canadian line of Bobby Clarke, Ron Ellis and Henderson, which was not expected to start for the team, as none were yet stars, played a surprisingly large role in the Canadian victory, with Henderson scoring the game-winning goal in each of the final three games. The series was filled with controversy, including disputes over officiating, and dirty play on the part of both teams highlighted by the deliberate slash of Kharlamov by Clarke in game six. There was also the exclusion of top Canadian player Bobby Hull, the second leading goalscorer in the NHL the previous season and who had led the league in goalscoring seven times, because he had signed a contract to play in the new World Hockey Association (WHA). A knee injury forced superstar defenceman Bobby Orr, the second leading point scorer in the league the previous season and scoring champion two years prior, to sit out.

Background From the beginning of the IIHF Ice Hockey World Championships in 1920, Canada would send a senior amateur club team, usually the previous year's Allan Cup champion, to compete as the Canadian entry. These teams were often university players or unpaid players playing ice hockey while being employed in some other profession full-time. From the 1920s until the 1950s, Canadian amateur club teams won most of the World Championship and Olympic titles. As a career, Canadian players would play instead in the various professional hockey leagues, the best reaching the NHL. Their professional status made them ineligible to play in the World Championships or Olympic Winter Games under the rules of the time. The last Canadian amateur club to win the world championship were the Trail Smoke Eaters in the 1961 championship.

In the earliest days of the Soviet Union, bandy or "Russian hockey" was played, not "Canadian hockey", and the Soviets did not compete in the Olympics or World Championships for ice hockey, which played the Canadian game. Post-World War II, a goal of the Central Committee of the Soviet Union was world supremacy in sport. The decision was made to transfer resources to the Canadian game. Starting in the 1940s, the Soviet Union started a Soviet hockey league playing the Canadian game. The elite sports societies of the Soviet Union, such as CSKA Moscow (Central Sports Club Army), Dynamo and Spartak, soon became the elite teams of the hockey league and supplied the players for the national team. Ostensibly amateurs, the players played hockey full-time and were paid by the government. The players had other titular professions; for example Moscow Dynamo players became officers of the KGB; CSKA Moscow players became officers in the army. This preserved a player's amateur status for Olympic and World Championship eligibility, and the players would have a career after their hockey playing days ended.

Entering international play in 1954, the Soviet national team, under the tutelage of Anatoly Tarasov, started to dominate the international competitions and won nine consecutive championships in the 1960s. In response, Canada developed a national team of its own. But Canada's best players usually became professionals, and the national team featured mostly university players. The Canadian team did not win any championships and was looked upon as a failure. By 1969, the Government of Canada had formed Hockey Canada, an organization to co-ordinate Canadian international play with its amateur organizations and the NHL. In July 1969, on a trial basis, the inclusion of nine professional players for any event for one year was agreed to by the IIHF. Canada entered a team with five professionals in the Izvestia tournament at Christmas in 1969, and nearly won the tournament. The IIHF then convened an emergency meeting in January 1970, and the rule allowing professionals was rescinded. In response, Canada withdrew from IIHF play. The 1970 IIHF World Championships, scheduled to be held in Canada for the first time, were transferred to Sweden after Canada refused to host the event.

Organization In the early 1970s, the idea of meetings between the national teams of the USSR and Canada began to be actively discussed again. Its main initiator was the Сhairman of the State Committee for Physical Culture and Sports of the USSR, Sergei Pavlov. The Canadian embassy in Moscow learned of the Soviets' interest in a series initially through reading an article in the Soviet Izvestia newspaper in the winter of 1971–1972. Diplomat Gary Smith, responsible for sport and cultural exchanges with the Soviet Union, read In December 1971 that the Soviets were looking for a new challenge in ice hockey. Smith met with Izvestia sports editor Boris Fedosov initially, then followed up with a meeting with Soviet hockey boss Andrei Starovoytov and other Soviet officials in January. The Soviets divulged that they were ready to play in a series between its national team and Canadian professionals. After the meetings, Canadian ambassador Robert Ford passed the matter to Ottawa to negotiate a series and Hockey Canada was given the task to nail down the terms for a series. In March, Canada proposed a round-robin tournament including Sweden and Czechoslovakia in September, with a fallback proposal for bilateral games instead. The Soviets agreed in principle with the resumption of ice hockey contacts with Canada, depending on the final conditions to be negotiated in April.

The negotiations for the series were finalized at the Hotel International Prague during the 1972 World Ice Hockey Championships in April 1972. A "Letter of Agreement" was agreed upon and was signed on April 18, 1972, by Joe Kryczka, the Canadian Amateur Hockey Association (CAHA) president, Starovoytov the Soviet Union Ice Hockey Federation general secretary, Bunny Ahearne the president of the IIHF, and former CAHA president Fred Page as the vice-president of the IIHF.

The two sides agreed on the terms: four games in Canada in early September, and four games later in the month in the Soviet Union. Kryczka also announced that two games were to be held in Sweden before the Moscow segment of the series as part of a celebration of the fiftieth anniversary of ice hockey in Sweden. He also announced that Team Canada hoped to play a game or two in Czechoslovakia in return for previous visits by Czechoslovak teams to Canada. NHL President Clarence Campbell issued a statement that the league fully supported the proposed series.

The two sides agreed to hold the series in September and play the games under international rules. The Canadians agreed to IIHF amateur referees in the Canada part of the series, and European referees in the Moscow games. The refereeing would use the international two referee system, not the one referee, two linesmen system in place in the NHL, and, at the time, being introduced into international play. The Canadian side agreed to the terms under the belief that the Canadians would have no difficulty winning under any set of conditions. Kryczka felt that the Soviets had demanded the concessions for their own benefit, believing that their team was already equal to any NHL team. The agreement stipulated that Soviet players were to be paid per game in Canada, and Canadian players were to be paid 5,000 Rbls per game in Moscow. It also stipulated the choice of referees was acceptable to both parties. Teams were limited to 19 players and a total of 30, including officials, with allowances for changes between the Canadian and Moscow segments.

During the summer, further details were settled. The Canadian games were scheduled for Montreal (Montreal Forum), Toronto (Maple Leaf Gardens), Winnipeg (Winnipeg Arena), and Vancouver (Pacific Coliseum) and the games in the Soviet Union were all to be held in Moscow at the Luzhniki Ice Palace. The NHL players at first objected to the September dates, suggesting dates in October or November when they would be in better shape but the idea was rejected by the Soviets. A game in Prague, at first proposed following the Swedish games and before travel to Moscow, was moved to take place after the Moscow series.

NHL players' union executive director and Hockey Canada director Alan Eagleson, while not involved in the initial negotiations, became a central figure in the organization of the series. Eagleson, who could call on a personal network of players, NHL owners, Hockey Canada executives and Canadian business, would be involved in most arrangements for the Canadian team. Eagleson would confide to Toronto Star reporter Alexander Ross, that he "un-negotiated" much of what had been negotiated between the governments. Eagleson placated the NHL owners by arranging that part of the series' proceeds would go to the NHL player's pension fund, reducing payments from the owners, and threatening to have his player clients play without NHL co-operation. Before the first game, Eagleson personally paid to settle a lawsuit won by a Montreal man, whose car had been destroyed in the 1968 Warsaw Pact invasion of Czechoslovakia. The court had ordered the Soviet team's hockey equipment seized to guarantee payment, threatening the start of the series.