Born in
Charlottenburg (today part of
Berlin), Erwin Planck was the fourth child of
Nobel Prize-winning physicist
Max Planck (1858–1947) and his first wife Marie, née Merck (1861–1909). His father held a professorship at the
Berlin Frederick William University since 1889 and had become a notable member of the
German Physical Society (DPG); his children grew up in the wealthy environment of the
Grunewald mansions colony. Having obtained his
Abitur degree in 1911, Erwin Planck pursued a career as an officer in the
German Army. In
World War I, he soon found himself a
prisoner of the
French forces in 1914. Planck returned to Germany in 1917 and was active on the
General Staff. There, he met Major
Kurt von Schleicher, the beginning of a lifelong friendship. After the war, Major Schleicher became head of the political department in the newly established
Ministry of the Reichswehr and, in 1920, appointed Planck his assistant. In January 1924, Schleicher sent him as a liaison officer to the
Reich Chancellery, where Planck also became a government official after he left the
Reichswehr armed forces in 1926. Upon the downfall of the
Brüning government in 1932, he became a deputy minister under Chancellor
Franz von Papen, and retained that post when Schleicher himself was appointed Reich Chancellor in December. Planck contributed to Schleicher's
Querfront to gain Nazi support for his government, though to no avail. After Schleicher resigned and
Adolf Hitler was appointed Chancellor on 30 January 1933, Planck went into temporary retirement and travelled abroad to
East Asia for a year. Shortly after he came back to Germany, Kurt von Schleicher and his wife were shot at their
Babelsberg home by members of the
Sicherheitsdienst (SD) in the
Night of the Long Knives on 30 June 1934. Planck tried in vain to get an explanation for his friend's murder. He also held several conspiratorial talks with Reichswehr General
Werner von Fritsch which, however, did not lead to any conclusion. In 1936, Planck changed career paths and went into business, becoming a leading employee at the
Otto Wolff corporate group, a large conglomerate in
Cologne. In 1939, he took over leadership of the Berlin branch office. In August 1939, on the eve of
World War II, a group including
Prussian Finance Minister
Johannes Popitz, Planck, and
Reichsbank president
Hjalmar Schacht approached General
Georg Thomas, head of the Defence Economy and Armament Office, asking him to thwart the outbreak of the forthcoming
invasion of Poland. Thomas agreed to write a memorandum to his superior,
OKW Chief
Wilhelm Keitel, in which he stated that a war against Poland would set off a world war that Germany could not win owing to massive supply problems. However, Keitel tried to allay Thomas's fears by telling him that Hitler was planning no such war. In 1940, Planck, Popitz,
Ulrich von Hassell and General
Ludwig Beck drafted a "
Provisional Constitution", on the assumption that the forthcoming attack on the
Western Front would lead to the overthrow Hitler's regime. Even afterwards, Planck stayed in the
conservative resistance circles around
Carl Friedrich Goerdeler and was involved in the preparations for the
20 July plot. This led to his arrest on 23 July 1944, after which he was taken to the
Gestapo headquarters at the
Reichssicherheitshauptamt (RSHA). Erwin Planck was
sentenced to death in a
show trial at the "
People's Court" (
Volksgerichtshof) on 23 October. On 25 October, Max Planck personally drafted a letter to Adolf Hitler pleading for Erwin's life, a plea that was ignored. Planck was executed by hanging on 23 January 1945 at
Plötzensee Prison in Berlin. == Memorial plaque ==