Beginning in 1925, some members of higher levels of the German nobility joined the Nazi Party, registered by their title, date of birth, NSDAP Party registration number, and date of joining the Party.

Following Kaiser Wilhelm II's abdication and the German Revolution, the German nobility, as a legally defined class, was abolished. On promulgation of the Weimar Constitution on 11 September 1919, all such Germans were declared equal before the law with all persons of formerly lesser rank.Article 109 of the Weimar Constitution constitutes: Adelsbezeichnungen gelten nur als Teil des Namens und dürfen nicht mehr verliehen werden ("Noble names are only recognised as part of the surname and may no longer be granted"). There were 22 heads of these former federal states: 4 German kings—of Prussia, Bavaria, Saxony, and Württemberg—6 grand dukes, 5 dukes, and 7 princes, who—along with all of their families—lost their titles and domains. Adolf Hitler, Hermann Goering, Heinrich Himmler, and other Nazi leaders frequently appealed to these former princes, and especially to Wilhelm II and his family, by expressing sympathy for a restoration of the abolished monarchies and other such lost inheritances.

From 1925, the newly formed Nazi Party began accepting these princes by their (abolished) former titles, and by their (abolished) princedoms, and registering these dukes, princes, and princesses as such, in the Nazi Party. There are two known Nazi Party lists of such princes and principalities. Of the first list Historian Malinowski notes: "of 312 families of the old aristocracy 3,592 princes joined the Nazis (26.9%) before Hitler came to power in 1933." The second, in the Berlin Federal archives, lists 270 princely members of the Nazi Party (1928–1942), of which almost half joined the Nazis pre-Hitler. The Berlin list named 90 direct senior heirs, to their 22 abolished principalities, and also included claimants to the (former) Imperial Crown of Wilhelm II.

After the proposed "fourth Kaiser" died fighting as a member of the Wehrmacht in 1940, Hitler issued the Prinzenerlass, prohibiting German princes from serving in the Wehrmacht, but not from the Nazi Party or its paramilitary units, the Sturmabteilung (SA) or the Schutzstaffel (SS). Some German states provided a proportionally higher number of SS officers, including Hesse-Nassau and Lippe. Such princes included SS–Obergruppenführer and Higher SS and Police Leader Josias, Hereditary Prince of Waldeck and Pyrmont.

German Empire and Kingdom of Prussia

Wilhelm II, German Emperor issued his statement of abdication as German Emperor on 9 November 1918. This was followed on 28 November by his abdication as King of Prussia, thus formally ending the House of Hohenzollern's 400-year rule over Prussia. He also gave up his, and his family's, future succession rights to the throne of Prussia and to the German imperial throne.

Wilhelm, German Crown Prince was first son and heir of Kaiser Wilhelm II. The Crown Prince is known to have abdicated around the same time as his father in 1918. Prince Wilhelm was a military commander, second in command to his commander-in-chief father, and served with Crown Prince Rupprecht of Bavaria and Albrecht, Duke of Württemberg, at German military headquarters throughout World War I, until the armistice of 11 November 1918. As such, Wilhelm II and Crown Prince Wilhelm directly commanded their chief of the General Staff, Paul von Hindenburg, throughout the war. During the war, Crown Prince Wilhelm awarded the Iron Cross, first class, to the future leading Nazi Hermann Göring, after Göring flew reconnaissance and bombing missions in the 25 (FFA 25) in the Crown Prince's Fifth Army.

In the early 1930s, Wilhelm II apparently hoped the successes of the German Nazi Party would stimulate interest in a restoration of the monarchy, with Crown Prince Wilhelm's son as the "fourth Kaiser". In 1933, Hindenburg, now Reich President of the Weimar Republic, appointed Nazi Party leader Adolf Hitler as the Chancellor of Germany. Crown Prince Wilhelm was a member of the , the conservative and nationalist veterans organization, which in 1931 had joined with the Nazis to form the Harzburg Front. Hitler visited the former Crown Prince at Cecilienhof three times, in 1926, in 1933 (on the "Day of Potsdam"), and in 1935. On Hindenburg's death in August 1934, Hitler officially abolished the presidency and became German head of state as , as well as Reich chancellor. This effectively forestalled the hopes of a Hohenzollern restoration at that time.

Prince Wilhelm of Prussia, the son of Crown Prince Wilhelm, nominated by Wilhelm as the "fourth Kaiser", took part in the invasion of France in May 1940. He was wounded during the fighting in Valenciennes and died on 26 May. His funeral service drew over 50,000 mourners. His death and the ensuing sympathy of the German public toward a member of the former German royal house greatly bothered Hitler, and he began to see the Hohenzollerns as a threat to his power. In 1940, Hitler issued the , which prohibited princes from German royal houses from serving in the .

Prince August Wilhelm of Prussia was the fourth son of Emperor Wilhelm II by his first wife, Augusta Victoria. He joined the Nazi Party on 1 April 1930 and was honored by being granted the low Nazi Party membership number 24. In April 1932, he was elected as a Nazi deputy to the Landtag of Prussia. At the 5 March 1933 election, he was elected as a deputy to the national from electoral constituency 4, Potsdam I."Prince August Wilhelm of Prussia". Reichstag Members Database In July, he was made a member of the Prussian State Council by Göring, now the minister-president of Prussia. As perhaps the most prominent member of the Hohenzollerns in the Nazi Party, the former prince hoped that Hitler would one day elevate him or his son Alexander Ferdinand to the vacant throne. A member of the Nazi paramilitary organization, the (SA), August Wilhelm was promoted to SA-, the second highest SA rank, in June 1939.

After the 1941 death of Prince August Wilhelm's father, the former Kaiser, and more so after making derogatory remarks about Joseph Goebbels, Prince August Wilhelm was denounced in 1942, sidelined, and banned from making public speeches. In February 1945, with former Crown Princess Cecilie, August Wilhelm fled the approaching Red Army to take refuge with his aunt Princess Margaret of Prussia in Kronberg. Arrested and imprisoned after the end of the war, he faced a denazification trial in 1948. He was sentenced to thirty months at hard labour but was released on the basis of time served. He died on 25 March 1949.

Prince Alexander Ferdinand was the only son of Prince August Wilhelm and his wife Princess Alexandra Victoria. Like his father, he hoped that Hitler would one day elevate him, or his son, to the vacant throne of the Kaiser. Their support for the Nazis caused disagreements among the Hohenzollerns, with Wilhelm II urging them both to leave the Nazi Party. In 1933, Prince Alexander Ferdinand quit the SA and became a private in the German Army. In 1934, Berlin reported that the prince quit the SA because Hitler had chosen the 21-year-old to succeed him as "head man in Germany when he [Hitler] no longer can carry the torch". The report also said that Göring, harboring his own ambitions for the succession, was expected to oppose the prince's nomination. In 1939, Prince Alexander Ferdinand was an in the signal corps. Unlike many princes distrusted and removed from their commands by Hitler, he was the only Hohenzollern allowed to remain in his post.

NSDAP Nazi PartyMilitary/ParamilitaryunitTitle andnameRoyalhouse Prussian princes in the Nazi Party NSDAP – 24 Joined: 1 April 1930 Prince August Wilhelm of Prussia Prussia Born 29 January 1887. Prince August Wilhelm of Prussia was the fourth son of Wilhelm II, German Emperor by his first wife, Augusta Victoria of Schleswig-Holstein. Prince August Wilhelm joined the NSDAP on 1 April 1930, with the low membership number 24. In 1931, he was accepted into the SA with the rank of SA-Standartenführer, rising to SA-Obergruppenführer by June 1939. Prince August Wilhelm hoped that Hitler would one day elevate him or his son Alexander Ferdinand to the vacant throne. NSDAP – 534782Joined: 1 May 1931 Prince Alexander Ferdinand of Prussia Prussia Born 26 December 1912. Prince Alexander Ferdinand of Prussia was the son of Prince August Wilhelm and Princess Alexandra Victoria. In 1933, Prince Alexander Ferdinand left the SA and became a private in the German Army. As of November 1939, he was an Oberleutnant in the Luftwaffe signal corps, stationed in Wiesbaden. NSDAP – 2407422Joined: 1 May 1935 Prince Karl Franz of Prussia Prussia Born 15 December 1916. Prince Karl Franz was the only child born to the Kaiser's youngest son Prince Joachim of Prussia and his wife Princess Marie-Auguste of Anhalt. In World War II, Karl Franz served as a in an armoured car division, and at one point was stationed on the Polish front. He was awarded the Iron Cross.

Kingdom of Bavaria

King Ludwig III may have been Hitler's first association with the imperial nobility. At the outbreak of World War I, Ludwig III received a petition from Adolf Hitler, asking for permission to join the Royal Bavarian Army. The petition was granted and Hitler joined the army, where he served for the remainder of World War I.For example:

This account is based on Hitler's recollections in . Kershaw holds that Hitler's story is simply not credible and suggests that bureaucratic error, rather than bureaucratic efficiency, was responsible for Hitler's enlistment; indeed, as a national of an allied country, he should have been sent to Austria for service in that army. Based on Bavarian government investigations in 1924, the more likely scenario in Kershaw's view is that Hitler applied for enlistment, along with thousands of other youths, on or about 5 August 1914, was initially turned away because the authorities were overwhelmed with applicants and had no place to assign him, and eventually was recalled to serve in the 2nd Infantry Regiment (2nd Battalion), before being assigned to Bavarian Reserve Infantry Regiment 16 (the List Regiment), which was principally made up of raw recruits.

As the war drew to a close, the German Revolution broke out in Bavaria, and Ludwig III was the first imperial monarch to be deposed. On 7 November 1918, King Ludwig fled from Munich with his family to Anif Palace, near Salzburg. On 12 November 1918, King Ludwig gave Prime Minister Dandl the Anif declaration, releasing all government officials, soldiers, and civil officers from their oath of loyalty to him. The republican government of Kurt Eisner declared the Wittelsbachs deposed, ending 700 years of Wittelsbacher rule over Bavaria.Anifer Erklärung, 12./13. November 1918 (in German) Historisches Lexikon Bayerns, accessed: 10 May 2008

Rupprecht, Crown Prince of Bavaria, Ludwig's son and heir, did not join the far right in Germany, despite Hitler's attempts to win him over through Ernst Röhm and promises of royal restoration. Rupprecht opposed Hitler, but a plan to give Rupprecht dictatorial powers in Bavaria under the title of , attracted support from a wide coalition of parties, even including the Social Democratic Party of Germany and Wilhelm Hoegner. However, the hesitancy of the Bavarian government under Minister-President Heinrich Held and Hitler's assumption of power in January 1933 ended all hopes for the idea."Royalty and Honour at War and Peace". London Magazine Rupprecht continued to harbor the idea of the "restoration of the Bavarian monarchy", in a possible union with Austria as an independent Southern Germany.

In a 1943 memorandum, Prince Rupprecht even mentioned his ambition for the German crown (of the German Empire), which had been held by the House of Wittelsbach in the past.

Kingdom of Saxony