“This is General Olbricht, calling on behalf of General Fromm, commander of the Reserve Army. The Fuhrer, Adolf Hitler, is dead. A group of radicals in the SS are attempting to seize control of the government. Initiate Operation Valkyrie.”

Bill Nighy delivered that line as General Friedrich Olbricht, one of the participants in the famous July 20 plot intended to assassinate Adolf Hitler, arrest members of his inner circle, and negotiate an armistice with the Allies. The bomb failed to eliminate their intended targets and the plotters were quickly arrested and executed. For a brief moment though, men like Claus von Stauffenberg, Ludwig Beck, Friedrich Fromm, Werner von Haeften, Henning von Tresckow, Carl Goerdeler, and Erwin von Witzleben believed that they had incapacitated the Nazis and rescued Germany.

Popularized in the 2008 film, Valkyrie, the July 20 plot became the most famous assassination attempt against Hitler, who by than had avoided death more than a dozen times. Members of the German Resistance were comprised of senior political, military, and private sector businessmen who lost faith that Germany could prevail against the Allies. U.S., British, and Canadian forces were in the midst of liberating France and renewed offensives by the Soviet Union on the Eastern Front placed Germany in an untenable position. In the early summer of 1944, after a failed bomb assassination, a new plan was put forward to resistance leaders.

The German Reserve Army (or Replacement Army) retained operational plans for maintaining law and order during a national emergency. Codenamed ‘Operation Valkyrie’, General Olbricht believed that it was possible to retool the plan to use the Replacement Army if a coup d’état were to erupt. Resistance members recruited the commander of the Replacement Army, Friedrich Fromm, who agreed to keep silent in exchange for a senior position in the new regime. Colonel Henning von Tresckow (who tried to kill Hitler in 1943) drafted a new copy of the Valkyrie plan and distributed it to various Nazi installations across Europe over a period of several weeks. The new draft required seizing communication hubs, government offices, and concentration camp offices so as to quickly secure German infrastructure.

But how to kill Hitler himself? There had been twenty-one attempts, including shooting, stabbing, bombing, and even poisoning (allegedly Hitler’s vegetarian diet spared him that fate). The answer came with Colonel Stauffenberg’s appointment as Chief-of-Staff of the Replacement Army. This granted him access to Hitler’s advisors and itinerary, which was manna from heaven to the Resistance. Armed with the knowledge of Hitler’s moving location and retinue, they could decide the method for killing Hitler. Two bombs armed with chemically timed pencil detonators inside a leather briefcase was the best option. The bomb would detonate inside a concrete bunker at the Wolf’s Lair complex in East Prussia and the resulting concussive blasts would instantly kill anyone in the room. Stauffenberg’s job required him to attend military briefings and so he volunteered to deliver the bombs.

The planners originally chose July 11 to carry out their mission, but there was a hiccup. Resistance members understood that if only Hitler was killed, he would be replaced by a close associate like Himmler or Goering. Ultimately the plan was aborted because Himmler wasn’t present at the briefing. A second attempt occurred on July 15 since Himmler and Goering were in attendance, but Hitler was called out for another meeting and Stauffenberg hastily removed the detonator from the bombs. Simultaneously as the Resistance carried out their plans, the Gestapo were investigating the alleged plotters and many concluded that some assassination attempt was in the works. Stauffenberg, Beck, Tresckow, Olbricht, and others resigned themselves to the fact that even if Hitler miraculously survived, they needed to complete the second half of their plot of seizing control of the German government. Failure meant facing the firing squad.

July 20, 1944: Stauffenberg and his adjutant, Lieutenant Werner von Haeften, arrived at the Wolf’s Lair and under the pretense of using a washroom, the two armed the bombs and walked to the briefing. A last minute change occurred when the meeting was moved from the concrete bunker to a wooden cabin with large windows: it was an especially hot and humid day. Stauffenberg placed the bomb as close as possible to Hitler and left the room quickly thereafter under the pretense of a phone call. At 12:42 PM, an explosion ripped through the cabin, shattering windows, ripping off doors, and splintering rafters. Believing Hitler was dead, Stauffenberg and von Haeften sped away from the Lair and flew back to Berlin where plotters received the flash: “HITLER IS DEAD.”

Hitler wasn’t dead. General Fellgiebel, another plotter present at the Wolf’s Lair, saw Hitler and informed other members, but when Stauffenberg arrived in Berlin, he maintained the Hitler was still dead. At 4:00 PM, Operation Valkyrie was initiated and the Replacement Army quickly went to work arresting ‘conspirators’ in the Nazi Party and Wehrmacht. As the plot continued though, news of Hitler’s survival began undermining the plan. Field Marshal Wilhelm Keitel deduced that Stauffenberg planted the bomb and orders for his and others arrests went out.

At around 7:00 PM, Hitler recovered enough from his mild injuries to begin making phone calls to Berlin. Members of the coup who wavered in their support for the Resistance shifted sides after hearing of Hitler’s survival. The coup quickly disintegrated and the plotters were ordered to be taken alive. In an attempt to prove loyalty, General held an impromptu court-martial and pronounced death sentences to all the conspirators. They were escorted to the courtyard of the Bendlerblock (administrative offices for the War Ministry), lined up, and shot to death.

In the weeks and months following the July 20 plot, dozens more conspirators were identified, admonished before kangaroo courts and summarily executed. It was the last assassination attempt against Hitler, but after World War II, it became the most famous attempt of them all since it came the closest to possibly ending the war. In those six hours on July 20, the Resistance had their chance of stopping the most savage fighting in all of Europe. They made the most of those hours before facing the gallows. Stauffenberg and his fellow conspirators became heroes in postwar world and their actions were later recognized by the German government in 1980 with the Memorial to the German Resistance. A plaque hangs above the spot where the plotters were executed, displaying a four solemn lines attributing to their cause:

You did not bear the shame.

You resisted.

You bestowed the eternally vigilant signal to turn back

by sacrificing your impassioned lives for freedom, justice and honour.