Dietrich Wilhelm Bernhard von Jagow (29 February 1892 – 26 April 1945) was a German naval officer, politician, SA-Obergruppenführer and diplomat. He served as the German ambassador to Hungary from 1941 to 1944, and committed suicide just before the end of the Second World War in Europe.

Early life and naval career Jagow was born into a distinguished aristocratic family in Frankfurt an der Oder. Gottlieb von Jagow, who served as the German foreign minister was his cousin. Jagow ascribed to the typical Junker values of militarism, nationalism and a deep devotion to serving the state. After attending the Mürwik Naval School, he joined the Imperial German Navy as a naval cadet on 1 April 1912. During the First World War, he served on surface ships and on U-boats. Jagow began the war in 1914 as a Leutnant zur See and, by the end of the war, had risen to the rank of Oberleutnant zur See and had been awarded the Iron Cross, 1st and 2nd class. After the armistice of 11 November 1918, he remained in the new Reichsmarine and commanded a torpedo boat and a minesweeper.

Völkisch activist In September 1919, Jagow joined the Marinebrigade Ehrhardt of the Freikorps and took part in the Kapp Putsch of March 1920. Refusing to take an oath of loyalty to the Weimar Republic, he left the Reichsmarine later in March 1920. Settling in Bavaria, he joined the right-wing terrorist group Organisation Consul that assassinated pro-Weimar politicians. His first job was as a sales agent for the Bavarian Wood Processing Company, which was a front for the Organisation Consul. In the fall of 1920, he joined the Nazi Party (NSDAP) and in early 1921 he joined the SA. In the spring of 1921, he fought against the Poles in Silesia. Jagow's company commander during the Silesian war was Baron Manfred von Killinger, who remained a close associate thereafter.

In January 1922, Adolf Hitler sent Jagow to set up the first NSDAP group in Tübingen, and Jagow subsequently became one of the most important Nazi leaders in Württemberg. Jagow worked as a guest lecturer at Eberhard Karls University. Jagow was also part of the management of the famous Osiander bookstore in Tübingen, a position he was able to secure as two other former naval officers were part of the management team. In April 1922 Hitler appointed Jagow SA inspector and chief of staff for Württemberg. As a professor, Jagow used his lecture podium as a chance to preach völkisch theories to his students.

German universities were traditionally strongholds of the völkisch movement, and the university town of Tübingen was a center of völkisch activities. The Social Democratic police president of Württemberg, Hermann Schützinger, who visited Tübingen in 1926 complained the city was very much dominated by the völkisch right. Schützinger noted that everywhere he went in Tübingen he saw photographs of Hitler and Erich Ludendorff prominently displayed "next to all kinds of antisemitic Germanic kitsch spat out by the metropolis" while "stubborn small-town professors" used their lectures to indoctrinate their students in the völkisch ideology. In such a climate, Jagow found his niche in Tübingen as a professor and SA leader. On 24 June 1922, the German foreign minister Walther Rathenau was assassinated by members of the Organisation Consul, which reviled him both as a Jew and a supposed contributor to "creeping communism" for having negotiated the Treaty of Rapallo with Soviet Russia. The subsequent police investigation into Rathenau's assassination led to Jagow being interviewed as a possible suspect, though he was never charged. However, the police investigation did establish that Jagow spent much of his time leading his students in paramilitary training for the Organization Consul, which appeared to be his primary duty at the university.

After the failure of the Beer Hall Putsch at Munich in November 1923, Jagow left the NSDAP, but remained active in a number of völkisch groups in Württemberg. From 1923 to 1927, he was a member of the Bund Wiking (Viking League). In 1925, he led a group of völkisch university students into a street fight with the Reichsbanner Rote-Schwartz-Gold, the paramilitary wing of the Social Democratic Party (SPD). In 1927, he joined Der Stahlhelm, the military veterans association. In January 1929, he rejoined the NSDAP (membership number 110,438). As an early Party member, he would later be awarded the Golden Party Badge. From 1929 to 1930 he was the NSDAP Ortsgruppenleiter (Local Group Leader) in Esslingen am Neckar and the managing director of the NSDAP Gau Württemberg-Hohenzollern. In 1931 Jagow was appointed full-time SA group leader "Southwest", placing him in charge of all SA units in southwestern Germany. Starting in 1931, Jagow was engaged in a feud with Fritz Bauer, the Social Democratic judge who served as the chairman of the Stuttgart chapter of the Reichsbanner Rote-Schwartz-Gold. As a Social Democrat, a Jew and a homosexual, Bauer personified everything that Jagow hated. Jagow was well known as a militant anti-Semite and a devotee of the Führer principle. On 9 May 1932, Jagow was appointed as a deputy to the Reichstag to fill a vacancy from electoral constituency 31 (Württemberg).Dietrich von Jagow entry in the Reichstag Members Database He remained a member of the Reichstag until his death in April 1945, representing electoral constituency 3 (Berlin-East) after the March 1936 election.

Under the Nazi Regime Starting in March 1933, Jagow served as the commissioner of the Württemberg state police. On 8 March 1933, Jagow was appointed police commissioner by Hitler using his powers under the Reichstag Fire Decree as a justification. As police commissioner, Jagow started what was described as a "reign of terror", allowing the Württemberg SA to beat up Jews, Communists and Social Democrats. On 9 March 1933, Jagow founded a hilfspolizei (auxiliary police) that consisted of members of the SA, SS, and the Stahlhelm under the pretext that a Communist revolution was imminent in Württemberg. On the night of 10 March 1933, Jagow had over 200 KPD members arrested without charge. Jagow had all of the offices belonging to the KPD and the SPD in Württemberg shut down as threats to public order. Shortly afterwards, Jagow had the hilfspolizei arrest the leaders of the Württemberg SPD and seized the offices and newspapers of the Social Democrats. In Stuttgart, he personally led the SA in shutting down the Communist and Social Democratic offices for Württemberg. Jagow seized all of the newspaper presses that belonged to the Communist and Social Democratic newspapers and then had the state of Württemberg sell the presses for a nominal sum to a Nazi publisher, Fritz Kiehn of Tubingen. The Nazis had much more success in winning the support of German Protestants while German Catholics by and large retained their loyalty to the Zenturm. As Germany was a Protestant majority country, this electoral limitation was not an insurmountable handicap but in Württemberg, which had a Catholic majority, the Nazis did not have the support of the majority of the people. Moreover, the working class of the industrial city of Stuttgart tended to vote for either the Social Democrats or the Communists. The sense of being a minority made the Württemberg Nazis inclined to use violent methods to impose their will on the population.

On 23 March 1933, Jagow used his powers as police commissioner was to have the Württemberg state police arrest his archenemy Bauer in his office without charges. Jagow had a concentration camp built at Heuberg and organised the boycott of Jewish businesses in Württemberg as part of the national boycott of Jewish businesses on 1 April 1933. The Heuberg concentration camp had 1,902 people imprisoned within its fences when it was founded in March 1933 and within nine months, the number had risen to 15,000. Bauer was sent to the Heuberg camp, where he was beaten and humiliated by the SA guards. About 40 people who were held at Heuberg died as a result of beatings by the SA guards during Jagow's time as police commissioner, a fact that he proudly noted in his reports to Berlin. The Württemberg NSDAP was torn by a feud between Gauleiter Wilhelm Murr and his rival, the Minister President Christian Mergenthaler. Jagow, who backed the losing side in the feud, was transferred to Frankfurt am Main as leader of the SA-Obergruppe V. On 27 June 1933, he was promoted to the rank of SA-Obergruppenführer and, on 14 September 1933, he was appointed a member of the recently reconstituted Prussian State Council. During the Night of the Long Knives, Jagow was scheduled for execution by the SS, and was lucky to have survived. Jagow was saved by Hitler's intervention, who insisted that Jagow was a good Alter Kämpfer ("Old Fighter") who served the NSDAP well during the Kampfzeit ("struggle time", i.e the Nazi term for the years 1923-1933). Jagow was transferred to Berlin, where he headed the SA-Gruppe Berlin–Brandenburg from July 1934 to January 1942. In Berlin, Jagow was noted for his zeal in persecuting Jews. He obtained a seat on the Provincial Council of the Province of Brandenburg in 1934 and, in July of that year, he also received a five-year appointment as a lay judge at the People's Court. In 1935, he was elected to a seat on the Berlin City Council.

In 1935, Jagow left the Evangelical Church of Württemberg, of which he had been a long-time member, saying that his belief in National Socialism was no longer compatible with membership in the Evangelical Church. Jagow had resumed his naval career in 1933 as a reserve officer and served during the Spanish Civil War in 1936–1937 as an intelligence officer. In 1936, when the völkisch magazine Das innere Reich was banned following an article which implicitly criticized the idolisation of Frederick the Great under the Third Reich, the editors of Das innere Reich appealed to Jagow among other people for help. On 23 October 1936, the ban of Das innere Reich was lifted following the intervention of Rudolf Hess.

On the outbreak of the Second World War in September 1939, Jagow resumed his active duty status in the Kriegsmarine with the rank of Korvettenkapitän, initially commanding the minesweeper Tannenberg in the Baltic Sea. Jagow was always proud to be a Junker and combined traditional Junker values with Nazism. In a letter to his son written in September 1939, Jagow encouraged him to remember the Jagow family values, which he called "the tradition of honour, loyalty, knightliness and bravery". In the same letter, Jagow told his son not to be a Duckmäuser ("moral coward") and to stay faithful to the "National Socialist idea unto death". From October 1940 to April 1941, he commanded the 18th Flotilla of patrol boats, torpedo boats, and minesweepers in the English channel, leading his forces into nightly clashes with the Royal Navy for control of the channel. On 1 May 1941, he was discharged from the Kriegsmarine, having earned the Clasp to the Iron Cross, 1st and 2nd class.