The July 20 Plot was a failed coup d'état which involved an attempt to assassinate Adolf Hitler. It was initiated on July 20, 1944 by officers of the Wehrmacht. The leader of the plot was Oberst Claus von Stauffenberg. Others who participated in the plot include Erwin Rommel and Alfred Delp.
The plan required Von Stauffenberg to place a time bomb near the seat of Hitler at the Wolfsschanze (Wolf's Lair) headquarters in Rastenburg, East Prussia, and then immediately travel to Berlin to command the troops of the uprising. A new government had already been formed. The code name for this plan was Operation Valkyrie.
However, due to unexpected circumstances, Hitler survived the bombing: because the day was unusually hot, the meeting at which Hitler was to have been killed took place above ground rather than in a bunker. Moreover, von Stauffenberg could arm only one of the two bombs and didn't place the unarmed one in the briefcase. Furthermore, Von Stauffenberg could not place the briefcase with the bomb next to Hitler and Hitler was shielded from the blast by the conference table. Although four people were killed and almost all present were injured, Hitler was so only lightly. Von Stauffenberg only learned of the failure later in Berlin.
Assuming Hitler was dead, Stauffenberg and Haeften flew to Berlin to meet up with their fellow conspirators in the Bendler-Block. Due to a misunderstanding, General Friedrich Olbricht did not launch Operation Valkyrie directly after the attempted assassination. Thus, the coup could only be set in motion four hours later, when Stauffenberg arrived.
In the course of the uprising, conspirators failed to win control over radio stations, therefore the news that Hitler had survived could not be suppressed. Reserve army troops in Berlin, which had carried out Stauffenberg's orders at the beginning, would soon refuse to continue doing so, causing the coup to collapse.
The plot ringleaders, Oberst Claus von Stauffenberg, General Friedrich Olbricht, Oberst Albrecht Mertz von Quirnheim and Lieutnant Werner von Haeften were caught in the late evening and shot by firing squad in the courtyard of the Bendler-Block (War Ministry) the same night.