At the opening ceremonies of the XXIII Olympic Winter Games, on February 9, 2018, something spectacular happened: Athletes from North and South Korea, which have been bitterly divided for 73 years, marched beneath a unified flag. Though North and South appear no closer to reunification, the move was seen as an olive branch of sorts that could pave the way for better relations between the estranged countries—and it’s just one example of how the worldwide sporting event can bring people together, if only for a few weeks.

It’s not the first time a divided nation has come together as one Olympic team. From 1956 through 1964, East and West Germany unified as a single team—until heightened political tensions tore the athletic programs apart.

At the end of World War II, the Olympics couldn’t be further from the minds of the German people. Their country had been decimated during the war, and in 1945, after Germany surrendered, the Allies split the country into four occupation zones. There was work to do: Not only did the Allies endeavor to root out Nazism from the remaining population, they also had to deal with millions of displaced persons, whose homes and families had been destroyed during the war and the Holocaust, and stabilize Germany’s collapsed economy.

In 1949, the western Allies—France, the United Kingdom and the United States—allowed their zones to self-govern, and the Federal Republic of Germany was born. Meanwhile, the USSR took over the eastern half of Germany and created the German Democratic Republic, a communist state. As daily life slowly normalized, both nations, which had been banned from competing in the 1948 games, began to look forward to the Olympic Games of 1952, 1956 and beyond.

The games meant similar things to both countries. They symbolized a celebration of the return of normal life, the end of a destructive war, and recognition of two new nations. But East and West Germany distrusted one another, and the Western world felt that to recognize an East German team would be to normalize and even celebrate the growth of Communism during the Cold War. To make matters even more complicated, East Germany was only recognized diplomatically by Eastern bloc countries.

West Germany set up its own National Olympic Committee, which was admitted into the International Olympic Committee in 1951 on the condition that Germany apologize for its wartime atrocities. But when East Germany tried to do the same thing, nearly simultaneously, it provoked political tensions. The IOC rejected the East Germans’ claim for an Olympic Committee on the basis that Germany already had one, and finally struck a compromise in which the East Germans could compete—but only if they did so under a unified team.

At first, East Germany refused, and did not compete in the 1952 games. (West Germany did, and brought home seven silver and 17 bronze medals.) East Germany grudgingly decided to join the West German team in a combined team in 1955, with the intention of competing in the 1956 games. “We have obtained in the field of sport what politicians have failed to achieve so far,” said Avery Brundage, the IOC president.

The German teams may have been unified in name, but they had some serious tensions to overcome. Some were relatively easy to address, like the question of which national anthem to use. Both countries decided to set aside their national anthems in favor of the “Ode to Joy” from Beethoven’s Ninth Symphony. Lodgings were easy to solve, too: Both countries stayed in the same quarters in the Olympic Village, and granted one another visas for training.

During the 1956 Winter Games, the unified team came away with a gold and a bronze, and in the summer games that same year, it won six gold medals, 13 silvers and seven bronzes.

But in 1959, tensions boiled over, as both countries bickered over which flag to compete under for the upcoming Summer Olympics in Rome. Initially, the athletes had competed under the former flag of united Germany, but that year East Germany introduced a flag that included the traditional German flag with the addition of a hammer and compass surrounded by a ring of rye. The flag had deep significance within the communist country—it represented the workers, farmers and intelligentsia. But to West Germany, it was a perversion of their national symbol.

The IOC tried to broker a compromise, making both teams march under the old flag with Olympic rings on it. Though both countries’ Olympic committees approved the plan, West Germany’s government complained about the potential of West German athletes marching under anything but the old flag. They threatened to pull West Germany from the 1960 games altogether.

“Should 53,000,000 Germans let themselves be blackmailed by a regime that is not even a legitimate democracy?” asked a spokesperson for German chancellor Konrad Adenauer’s party at the time.

Finally, the West German government capitulated and marched under the compromise flag suggested by the IOC, but the issue led to ongoing tension. So did the matter of visas: During the 1960 Winter Games in Squaw Valley, California, the United States denied several East German team members visas due to its ongoing lack of diplomatic relations with East Germany—meaning the athletes could not compete. And in 1961, the building of the Berlin Wall made things even worse. West Germany began to refuse visas to East German athletes, and East Germany retaliated. The West German sporting association also started forbidding East Germans from competing in its national competitions and prevented West Germans from going to the GDR to compete. The tense truce between East and West began to disintegrate.

Then, in 1968, the IOC recognized East Germany’s claim for a national committee. This was the beginning of the end for the combined team. Both teams began to compete separately, but still marched together during the opening ceremony under the compromise flag. But in 1972, the Olympics were held in Munich, West Germany—and the GDR competed with its own team and national anthem on what was, by then, enemy ground. East Germany flooded the press with negative reactions to the very idea of the games being hosted in West Germany, including implying that West Germany was still a Nazi state. The country even lobbied to prevent the Olympic torch from going through the USSR and its ally states. It failed—so it focused on performing well at the games instead.

Ultimately, East Germany edged out West Germany with 66 medals (West Germany won 40). However, the games are largely remembered not for tension between the two states, but for the massacre in which Palestinian terrorists killed 11 Israeli team members.

The separation of the teams had deep significance for both countries. “Perhaps more than any other sector of public life, Olympic sport confronted its functionaries with the unadulterated fact of German division,” wrote historians Kay Schiller and Christopher Young in their book, The 1972 Munich Olympics and the Making of Modern Germany.

From then on, the countries were irrevocably separate on the Olympic field, and political boycotts further separated the two teams at the Olympics in the years that followed. Another separation came in terms of training: Desperate for recognition and medals, East Germany began a state-sponsored doping program in the 1970s that earned its team success, but affected the bodies and lives of young competitors who were recruited by the state to bring East Germany to victory. Though the program was suspected for years, it was only uncovered in 1993, three years after East Germany ceased to be a state.

Only after the Berlin Wall fell in 1989 did Germany reunify at the Olympics. Since 1990, the team has been one again after 45 years of tension and separation. Though the North and South Korean teams are not entirely unified—only 10 North Korean athletes will compete in 2018, compared with 122 from South Korea, and the only event in which they will compete as one team is women’s ice hockey—marching under the same flag is a reminder of the inspirational, and symbolic, power of athletics and the Olympic Games.