Roughly 200 German resisters participated in “Operation Valkyrie,” the failed July 20, 1944, plot to assassinate Adolf Hitler and overthrow the Nazi regime. To this day, historians debate what motivated these “men of July 20.” At least initially, Hitler’s authoritarianism, anti-Semitism and predilection for mass murder didn’t necessarily put them off. Yet as World War II rolled on, they came to share a belief that the Führer was disgracing Germany and leading it to ruin.

Hitler largely took power through the democratic process, but he quickly established a dictatorship in which dissent was not tolerated. Hundreds of thousands of perceived opponents found themselves imprisoned in concentration camps, while others were killed outright. Even the slightest provocation risked incurring Hitler’s wrath.

Given this hostile climate, most Germans who had voted against him kept a low profile, explains Peter Hoffmann, a history professor at McGill University who specializes in the German resistance movement during World War II.

Nonetheless, a small minority remained relatively uncowed. These dissidents, though never “a statistically relevant” percentage of the German population, actively “tried to bring down Hitler’s government,” Hoffmann says. To that end, they hatched more than 40 assassination plots.

The best-known among these plots—and the one that arguably came closest to succeeding—occurred on July 20, 1944, when Claus von Stauffenberg (played by Tom Cruise in the movie Valkyrie) snuck a briefcase bomb into a meeting with the Führer.

Many of the July plot’s participants were, like Stauffenberg, high-ranking military officers of aristocratic descent. “They were often the traditional elite, the best educated, with foreign connections, and with a sense of obligation to the idea of Germany,” says Roger Moorhouse, an historian who has written several books on Nazi Germany, including Killing Hitler: The Third Reich and the Plots Against the F__ü__hrer. He adds that the aristocracy tended to view the Nazis “with distaste, not least on class grounds.”

Some of the main plotters, as Moorhouse points out, were “principled opponents of the Nazis from the outset.” Henning von Tresckow, for instance, privately disavowed the regime as early as 1935, following the passage of the Nuremberg race laws.

Then, in July 1941, Tresckow learned of the mass killing of Jews. At that moment, Hoffmann explains, he dedicated himself to deposing Hitler, forming a cell that initiated several assassination attempts, culminating in Operation Valkyrie. “It was a question of personal honor,” Hoffmann says, “and the need to prove to the world that there were Germans who had tried for years to bring the killing and destruction to an end.”

Stauffenberg likewise came to view Hitler as a monster. Yet he was among those who joined the resistance late, having apparently been seduced by the initial successes of the Nazi war machine. During the 1939 invasion of Poland, he wrote that the “inhabitants are an unbelievable rabble” who would surely only be “comfortable under the knout,” and that “the thousands of prisoners-of-war will be good for our agriculture.” In a tacit sign of support for the regime, he even wed in a steel military helmet and honeymooned in Fascist Italy.

A few of the plotters committed horrific war crimes. Wolf-Heinrich von Helldorf, Berlin’s police chief, was notorious for harassing and extorting Jews; Arthur Nebe commanded a mobile death squad that murdered tens of thousands of Jews in territory conquered from the Soviet Union; and Georg Thomas was a driving force behind the so-called Hunger Plan, which aimed to starve to death millions of Soviet civilians.

Eduard Wagner, who provided Stauffenberg with a plane for the July 20, 1944, assassination attempt, was perhaps worst of all. Christian Gerlach, a professor of modern history at the University of Bern in Switzerland, who writes about the Holocaust, describes him as “a leading mass murderer,” responsible for “all sorts of atrocities,” including the “ghettoization of Jews” and the starvation of Soviet prisoners. Wagner moreover advocated for the siege of Leningrad, Gerlach says, “in which at least 600,000 civilians died, mainly of hunger and cold.”

Despite their increasing alarm over the regime’s excesses, nearly every plotter turned a blind eye to Nazi atrocities at one point or another. Even Tresckow oversaw the wholesale destruction of villages on the Eastern Front. “This was not unanimously an ‘uprising of the conscience,’ as it has been stated by some historians,” Gerlach says. “The [July 20] coup was about perceived German national interests and how to pursue them.”

To their credit, the plotters wanted to end the war. They also eschewed military rule, tapping politicians and other civilians to take over the reins of government in the wake of any coup. As Gerlach points out, however, certain members opposed a transition to democracy, preferring instead a “kind of corporative state, perhaps a semi-authoritarian state.” He adds that several plotters “wanted to keep some annexed territories.”

By mid-1944, as the Americans and British closed in from the West and the Soviets closed in from the East, a new motivation emerged: Saving the homeland from complete destruction.

“There was no longer any hope of avoiding military occupation by the Allied powers, no question of seizing power and holding on to it, no question of any political perspective for the plotters even if they succeeded,” Hoffmann says, adding that they simply wanted to prevent an invasion of Germany and halt the killing.

But they never got a chance to enact their vision. On July 20, 1944, Stauffenberg placed an explosives-laden briefcase close to Hitler during a meeting at the Wolf’s Lair military headquarters in present-day Poland and then left the room under the pretext of a phone call. The subsequent blast mortally wounded a stenographer and three officers. But Hitler emerged barely scathed, purportedly because one of the officers killed had moved the briefcase so as to better view a map on the table. Hitler's pants became shredded by the blast and he suffered a perforated eardrum, but he was alive.

Stauffenberg, who had lost his left eye, his right hand and some fingers on his left hand during the war, immediately flew back to Berlin to launch the planned uprising to overthrow the regime.

When it became clear that Hitler had survived, however, the coup attempt withered. Betrayed by one of his co-plotters, Stauffenberg was executed that night, though not before shouting “Long live holy Germany” as he faced down the firing squad. _“_Stauffenberg was the wrong man for this,” another plotter later said, “but no one else had the guts.”

In the following weeks, the Nazis put to death nearly all 200 of the remaining plotters, in some cases brutally stringing them up from meat hooks. The assassination attempt likewise triggered a crackdown on thousands of other alleged dissidents. Caught in the dragnet was Erwin Rommel, the popular general who was forced to commit suicide despite scant evidence that he participated in the conspiracy.

A few lucky plotters survived the war, the last of whom died in 2013. Originally considered traitors by a large segment of the German population, the “men of July 20” eventually transformed into heroes in the public eye. Since 2002, German military recruits have ceremonially sworn their oaths on July 20 in honor of Stauffenberg and his cohorts.