Heusinger was born in Holzminden, in the Duchy of Brunswick, German Empire. He entered the Prussian Army in 1915, becoming an officer in 1917. Following the war, Heusinger was retained in the Reichswehr of the Weimar Republic. In 1931, Heusinger was assigned to the operations staff of the Troop Office in the Ministry of the Reichswehr, the German Army's covert General Staff in circumvention of the Treaty of Versailles, which forbade that institution. In August 1937, Heusinger was assigned to the Operations Staff of the re-established Army General Staff of Wehrmacht. He served there, being promoted to lieutenant colonel on March 20, 1939, and remained in that position until October 15, 1940, when he became its chief.
World War II
With the outbreak of the Second World War, the German Army High Command assumed its wartime organization. Heusinger accompanied the field staff and assisted in the planning of operations for the invasions of Poland, Denmark, Norway, and France and the Low Countries. He was promoted to colonel on August 1, 1940, and became chief of the Operationsabteilung in October 1940, making him number three in the Army planning hierarchy, after the Chief of the General Staff, General Franz Halder, and the Deputy Chief of the General Staff/Chief Quartermaster, General Friedrich Paulus. After the invasion of the Soviet Union in June 1941, the OKH became primarily responsible for planning operations in that theater, while the Armed Forces High Command was responsible for other theaters. Halder was replaced as Chief of the General Staff in September 1942 by General Kurt Zeitzler. Heusinger remained chief of the Operationsabteilung and was promoted to Generalleutnant on January 1, 1943. In June 1944, Zeitzler became ill, and on June 10, Heusinger temporarily assumed his office as Chief of the General Staff of the Army. In this capacity, he attended the meeting at Adolf Hitler's Wolf's Lair on July 20, 1944, and was standing next to Hitler when the bomb planted by Claus von Stauffenberg exploded. Heusinger was hospitalized for his injuries in the explosion, but afterwards was arrested and interrogated by the Gestapo to determine his role, if any, in the July Plot. Although there was evidence that Heusinger had had contacts with many of the conspirators, there was insufficient evidence to directly connect him to the plot, and he was freed in October 1944. However, he was placed into the "Führer-Reserve" and was not assigned to another position until March 25, 1945, when he was made chief of armed forces mapping department. He was taken prisoner by the Western Allies in May 1945.
Post-World War II
An internee from 1945 to 1947, Heusinger testified during the Nuremberg Trials. In 1950, he became an advisor on military matters to Konrad Adenauer, the first Chancellor of West Germany. He served in the Blank OfficeAmt Blank, the office headed by Theodor Blank, which became the West German Ministry of Defense in 1955. on 12 November 1955 With the establishment of the West Germany Armed Forces Bundeswehr in 1955, Heusinger returned to military service. He was appointed a Generalleutnant on November 12, 1955, in the Bundeswehr and chairman of the Military Leadership Council. In March 1957, he succeeded Hans Speidel as chief of the Bundeswehr's'' all-armed forces department. in Washington, D.C., 1964 Shortly thereafter, in June 1957, Heusinger was promoted to full general and named the first Inspector General of the Bundeswehr, and served in that capacity until March 1961. In April 1961, he was appointed Chairman of the NATO Military Committee in Washington, D.C., where he served until 1964, when he retired. He was, according to news reports, wanted by the Soviet Union in the early 1960s for war crimes committed in the occupied Soviet territories. Heusinger died in Cologne on November 30, 1982, aged 85. According to documents released by the German Federal Intelligence Service in 2014, Heusinger may have been part of the Schnez-Truppe, a secret army that veterans of the Wehrmacht and Waffen-SS sought to establish in the early '50s.
