Klaus Bonhoeffer was born in Breslau, Germany, now Wrocław, Poland, to Karl Bonhoeffer, a professor of psychiatry and neurology, and his wife Paula (née von Hase), as their third son. His younger brother was the theologian Dietrich Bonhoeffer (4 February 1906 – 9 April 1945). As a child, he went to the Grunewald-Gymnasium in Berlin with Hans von Dohnanyi.
He studied law at Heidelberg and received a doctorate for his thesis, "Workers' Committees as an Organ of the Workers' Coöperative" (Die Betriebsräte als Organ der Betriebsgenossenschaft). He also had further training in Berlin, at the University of Geneva, and in Amsterdam.
He worked as a lawyer and from 1935 as a legal adviser for Deutsche Luft Hansa, serving from 1937 to 1944 as chief syndic. This job took him on many business trips, even during the war.
In the years 1940–1944, he systematically forged contacts with various resistance groups working against the Nazi régime. Through his brother Dietrich, he had contacts with the church resistance, and through his brothers-in-law, Justus Delbrück, Dohnanyi and Rüdiger Schleicher, he had many contacts in the military resistance to Hitler, especially in the circle about Wilhelm Canaris in the Abwehr of the Oberkommando der Wehrmacht. Through his wife's cousin Ernst von Harnack, he was connected to the social-democratic resistance. Klaus Bonhoeffer also led his colleague Otto John, among others, into the resistance. He used his travel opportunities to further the cause against the Nazis. He was dedicated to the plan to assassinate Hitler on 20 July 1944 and overthrow the government.
According to the detention book kept at the Lehrter Straße prison in Berlin, where the Gestapo had a special section for political prisoners, Bonhoeffer was arrested on 1 October 1944 and sentenced to death by the German "People's Court" (Volksgerichtshof) on 2 February 1945. On the night of 22–23 April, as Soviet troops were already reaching Berlin's eastern outskirts, he along with Rüdiger Schleicher and other prisoners was taken by a special squad from the RSHA to the exhibition grounds near the Lehrter Straße prison and killed with a gunshot wound to the neck.
The only eyewitness to these murders was Herbert Kosney, who managed to move his head at the last moment so that the shot meant for his neck missed.
On 3 September 1930, he wed Emmi Delbrück, who was Hans Delbrück's daughter, and Justus and Max Delbrück's sister.
Emmi Bonhoeffer (née Emilie Delbrück) was the wife of anti-Hitler activist Klaus Bonhoeffer. She was born on May 13, 1905, in Berlin. She married Bonhoeffer on September 3, 1930.
Klaus was chief counsel of the Lufthansa Airline Company and was the leading civilian member of the military resistance to the Hitler regime. While occupied with raising their children, Emmi supported her husband's decision to oppose Nazism, assisting him on countless occasions both morally and practically. Her husband was arrested in October, 1944 in connection with the plot to kill Hitler. He was sentenced to death in February, 1945, and killed by the SS as the war was ending on April 23, 1945.
Emmi barely escaped her own death when her house was destroyed in the last days of the war. She moved with her children to Schleswig-Holstein to start a new life in June, 1945. She was active in projects aiding war refugees, as well as anti-Nazi educational work and various humanitarian efforts.
Emmi participated in Thames Televisions acclaimed historical documentary, The World At War, in Episodes 1 and 16. Here, Emmi describes her and her husband Klaus experience of Kristallnacht in 1938.
Emmi Bonhoeffer was also the author of Auschwitz Trials: Letters from an eyewitness.
She died on March 12, 1991, in Düsseldorf.
