Little detail is known of his early years in the parental home and the education he received. The first reference to Gehre appears when he was a managing director of a building contractor. In 1928 he published a study on Clausewitz.
By that time he is supposed to have begun his career as an officer in the Reichswehr.
At the beginning of the Second World War Gehre was active as a Captain in the Abwehr (Military Intelligence) under Admiral Wilhelm Canaris. By 1939 a group in the Abwehr had formed to remove the Nazi regime and end the War.
This circle included Admiral Canaris, General Ludwig Beck, Hans von Dohnanyi, Hans Oster, and Dietrich Bonhoeffer, as well as Gehre. By March 1943 Gehre was privy to the Military Opposition"s preparations under Henning von Tresckow to assassinate Hitler.
In January 1944 Helmuth James Graf von Moltke was arrested, and in March 1944 Gehre was also taken by the Gestapo.
Gehre, however, was soon able to flee and disappeared. After the failed 20 July 1944 assassination attempt to kill Hitler, the search for Gehre intensified. Further shelter was procured by the brothers Hans and Otto John.
Although he was badly hurt, he survived.
On 1945 February 3 the building of the Central Reich Security Office on Prinz-Albrecht-Straße, Berlin was destroyed. Gehre, along with Bonhoeffer, was sent to the Buchenwald concentration camp.
From there he was put onto a transport of Steamship special detainees and on April 5 incarcerated in the Flossenbürg concentration camp. On April 9, 1945, after an Steamship flying court-martial, Gehre and Bonhoeffer along with Admiral Canaris, General Oster, General Sack and Captain Theodor Strünck were executed at Flossenbürg by hanging.
In 1946 the individuals who had participated in the flying court-martial were brought to justice for murder.
However Otto Thorbeck, the presiding officer, was exonerated after appeal. The decision was rescinded by the Berlin State Court in 1996. Web References.