Leo von Jena, also called Leo Ferdinand von Jena (July 8, 1876 - April 7, 1957), was a German military officer who became an Schutzstaffel (SS) general during World War II and commander of the Waffen-SS in Berlin. Von Jena joined the German National People's Party and the Sturmabteilung (SA) in 1921. He joined the Nazi Party in 1936. On November 9, 1936, he joined the Schutzstaffel and Heinrich Himmler personally accepted him as an honorary Sturmbannführer, where he rose through the SS ranks. On March 30, 1941, he was promoted to Brigadeführer of the Waffen-SS. On January 30, 1944, he was promoted to Obergruppenführer of the Allgemeine SS and Lieutenant General (Generalleutnant) in the Waffen-SS.
World War I
Von Jena was the eleventh child of the Prussian officer and later general of the infantry Eduard von Jena (1834–1911) and his first wife Elisabeth Auguste Karoline Helene, née Freiin von Dalwigk (1840–1880).
In May 1896 he joined the cadet corps (Kadettenkorps) with the Life Grenadier Regiment König Friedrich Wilhelm III. (1st Brandenburg) with the rank of Fahnenjunker. On November 18, 1897, he was promoted to second lieutenant and assigned to the war school in Danzig. In May 1902 he transferred to the Holstein Field Artillery Regiment No. 24 in Güstrow. Between April 30, 1903, and 1911 he served in various military units. On February 18, 1908, Jena was promoted to Oberleutnant. In 1911 he became adjutant of the Landwehr district of Frankfurt (Oder). In September 1912 he became an aid and adviser to Prince Friedrich Leopold of Prussia. On October 18, 1912, he was promoted to Hauptmann (captain). In August 1913 von Jena was appointed personal adjutant to Prince Friedrich.
At the beginning of World War I in August 1914, he joined the 2nd Cavalry Division in Belgium and France. On 21 October 1914 he married his then-fiancée Josefine Margarethe Schumacher. In December 1914 he became a company commander and battalion commander in the 5th Guards Regiment in Masuria, East Prussia. In the spring of 1915, von Jena was deployed back to France and suffered a knee injury during the Second Battle of the Marne. After recovery, he was deployed to the reserve battalion of the 5th Guards Regiment in Spandau, where he was appointed deputy adjutant of the 4th Guards Infantry Brigade in the fall of 1915. Soon he transferred to the Landwehr division of the Guards Corps. In November 1916 von Jena was promoted to commander of the 1st Battalion of the 4th Foot Guards Regiment and assigned to the staff for the 1st Foot Guards Regiment in October 1917. Towards the end of the war, von Jena was commander of Reserve Infantry Regiment No. 932.
Weimar Republic
Von Jena viewed himself as a victim of the November criminals, those that lost in the war due to an antisemitic conspiracy theory. On December 16, 1918, he founded the National Association of German Officers with other officers loyal to the monarchy, like Alfred Krauss. On January 12, 1919, von Jena joined one of the approximately 200 Freikorps in Germany. In Berlin he became leader of the Volunteer Detachment Jena in the Freikorps von Oven. In 1919 von Jena was accepted as a captain in the provisional Reichswehr army and was promoted to major in October 1919 of Reichswehr Infantry Regiment 6. On December 31, 1920, von Jena was released from the Reichswehr at his own request. On January 1, 1921, he was employed by the Reichswehr leadership as leader of the clean up command of the Reichswehr Infantry Regiment 6. In 1921 he joined Alfred Hugenberg's German National People's Party and became a leader in its military arm, the Stahlhelmbund, where he met Prussian Lieutenant General Paul Hausser. In the Stahlhelmbund he became the liaison officer of the Bund to the German ex-Kaiser Wilhelm II and was on friendly terms with him. He stayed several times with Wilhelm II in exile at Doorn in the Netherlands.
National Socialism
In 1934 von Jena joined Wilhelm Reinhard's Kyffhäuserbund for war veterans in Berlin. The veterans group became aligned with Adolf Hitler's Sturmabteilung (SA). Thus von Jena joined the Reichsbetriebszellenabteilung (Spandau Comradeship of Life Grenadiers No. 8) of the Nazi Party.