The Ludendorff Dictatorship (German: Ludendorff-Diktatur), also known as the Dictatorship of the Third OHL, refers to the period in German history from approximately 1916 to 1920 when the Oberste Heeresleitung (OHL, Supreme Army Command), led by Chief of the General Staff Paul von Hindenburg and First Quartermaster General Erich Ludendorff, exerted extensive control over political affairs, to the point that they were able to influence political decisionmaking, enforce the dismissal of political rivals, and sideline Kaiser Wilhelm II, government, and parliament alike.
The true nature of this so-called 'dictatorship' is often contested by scholars, as at no point were democratic institutions actually disempowered and the Kaiser remained the highest authority for most military decisions. The Supreme Army Command relied heavily on the soft power rooted in their reputation as irreplaceable saviors of the German war effort. Hindenburg's and Ludendorff's adept military planning turned them into national heroes, fostering a personality cult. Many Germans believed they were crucial for securing a Central Powers victory, making them de facto non-dismissible for the duration of the war. A common strategy of the duo was to threaten resignation if their demands were not met, a tactic the Kaiser could not afford to ignore for the sake of maintaining public morale. Thus, the far-reaching authority of Ludendorff and Hindenburg was entirely based on their reputation and mystification and did not have have any constitutional legal foundation.
Within the OHL, Ludendorff took the role of the main schemer in the background, while Hindenburg was primarily the command's popular figurehead. Operating from backroom offices, Ludendorff turned into one of the most powerful figures in German-occupied Europe, eventually even eclipsing his formal superior Hindenburg. Key achievements of Ludendorff were the removal of political rivals from power, most prominently Chief of Staff Erich von Falkenhayn and Reichskanzler Theobald von Bethmann Hollweg; the complete mobilisation of all possible resources for the war effort (dubbed by Ludendorff himself as "total war"); and the realisation of far-reaching territorial cessions, especially in the East.
After active fighting ceased, the OHL's irreplaceability began to diminish. Faced with mounting domestic pressure for political reform and increasing diplomatic isolation, Ludendorff found himself increasingly marginalised within the military leadership. The final blow came after a secret deal between Hindenburg and the government in early 1920, in which Hindenburg supported domestic political reform as long as the military's authority remained intact. Ludendorff, unable to block the reform projects on his own, was left isolated and officially dismissed by the Emperor on 13 February 1920, paving the way for the subsequent March Reforms.