On the outbreak of the First World War Witzleben he was appointed Adjutant of the 19th Reserve Brigade. He served on the Western Front where he won the Iron Cross. In April 1917, Witzleben assumed command of a battalion in the 6th Infantry. The following year he became General Staff Officer to the 108th Infantry Division.
Witzleben remained in the army and in January 1921 was given command of the 8th Machine Gun Company. He was on the General Staff of the Wehrkries IV (1922-25), 12th Cavalry Regiment (1925-26) and Infantry Command III (1926-28). W became Chief of Staff of Wehrkries IV (1929-31) and commander of the 8th Infantry Regiment (1931-33).
In 1934 Witzleben was promoted to major general and appointed commander of Wehrkries III, replacing General Werner von Fitsch, who was named Commander in Chief of the Army.
An opponent of Adolf Hitler and his government in Nazi Germany, Witzleben joined with Erich von Manstein, Wilhelm Leeb and Gerd von Rundstedt to demand a military inquiry into the death of Kurt von Schleicher following the Night of the Long Knives. However, the Defence Minister, Werner von Blomberg, refused to allow it to take place.
Witzleben was furious when his friend, General Werner von Fitsch, was dismissed as Commander in Chief of the Army on a trumped up charge of homosexuality. He was now a staunch anti-Nazi who began considering the possibility of a military coup against Hitler. The Gestapo became aware of his criticisms of Hitler and in 1938 he was forced to take early retirement. Witzleben plotted with anti-Nazis such as Ludwig Beck, Franz Halder, Wilhelm Canaris, Hans Oster, Wolf von Helldorf, Kurt Hammerstein-Equord and Erich Hoepner and they considered the possibility of a military coup.
On the outbreak of the Second World War Witzleben was recalled to the German Army. In the invasion of France Witzleben commanded the 1st Army. His troops broke through the Maginot Line in June, 1940 and then occupied Alsace-Lorraine. As a result of this action Witzleben was promoted to the rank of field marshal.
Witzleben remained in France and after the failure of the Operation Barbarossa he once again began plotting against Adolf Hitler. The Gestapo was informed that he was once again being critical of the government and in 1942 Witzleben was called back to Germany and retired.
Witzleben spent the next two years at his country estate. He kept in touch with anti-Nazis and in 1944 became involved in the July Plot. After Claus von Stauffenberg planted the bomb the conspirators thought that Hitler had been killed and Witzleben was installed as Commander in Chief of the Armed Forces and Erich Hoepner as Commander of the Home Army.
On 21st July, 1944 Witzleben was arrested and during his trial he was humiliated by being forced to appear in court without his belt and false teeth. Erwin von Witzleben was found guilty of treason and on 8th August, 1944 was executed by being hung by piano wire from a meat hook.
I will crush and destroy the criminals who have dared to oppose themselves to Providence and to me. These traitors to their own people deserve ignominious death, and this is what they shall have. This time the full price will be paid by all those who are involved, and by their families, and by all those who have helped them. This nest of vipers who have tried to sabotage the grandeur of my Germany will be exterminated once and for all.
To create order, I have appointed Himmler Commander of the Reserve Army. I am convinced that with the disappearance of this very small clique of traitors and conspirators we are finally creating in the homeland the atmosphere which the fighters at the front need.
It is unthinkable that at the front, hundreds of thousands, no millions, of good men should be giving their all while a small gang of ambitious and miserable creatures here at home tries perpetually to sabotage them. This time we are going to settle accounts with them in the way we National Socialists are used to doing.
Imagine a room with a low ceiling and whitewashed walls. Below the ceiling a rail was fixed. From it hung six big hooks, like those butchers use to hang their meat. In one corner stood a movie camera. Reflectors cast a dazzling, blinding light. At the wall there was a small table with a bottle of cognac and glasses for the witnesses of the execution. The hangman wore a permanent leer, and made jokes unceasingly. The camera worked uninterruptedly, for Hitler wanted to see and hear how his enemies died. He had the executioner come to him, and had personally arranged the details of the procedure. "I want them to be hanged, hung up like carcasses of meat." Those were his words.
Field Marshal Witzleben freely admitted his part in the assassination attempt. He and the others were found guilty the next day and sentenced to hang that afternoon. Hitler had ordered that they be hung like cattle. "I want to see them hanging like carcasses in a slaughterhouse!" he commanded. The entire event was filmed by the Reich Film Corporation. Witzleben was first. Despite his poor showing at the trial, Witzleben met his death with courage and with as much dignity as was possible under the circumstances. A thin wire noose was placed around his neck, and the other end was secured to a meat hook. The executioner and his assistant then picked up the sixty-four-year-old soldier and dropped him so that his entire weight fell on his neck. They then pulled off his trousers so that he hung naked and twisted in agony as he slowly strangled. It took him almost five minutes to die, but he never once cried out. The other seven condemned men were executed in the same manner within an hour. They were followed over the next eight months by hundreds of others.