Otto Wels was a German politician who served as a member of the Reichstag from 1912 to 1933 and as the chairman of the Social Democratic Party (SPD) from 1919 until his death in 1939. He was military commander of Berlin in the turbulent early days of the German Revolution of 1918–1919, and during the 1920 Kapp Putsch he was instrumental in organizing the general strike that helped defeat the anti-republican putschists. Near the end of the Weimar Republic's life, however, he saw the futility of calling a general strike against the 1932 Prussian coup d'état because of the mass unemployment of the Great Depression.

The German Revolution of 1918–1919, also known as the November Revolution, was an uprising started by workers and soldiers in the final days of World War I. It quickly and almost bloodlessly brought down the German Empire, then in its more violent second stage, the supporters of a parliamentary republic were victorious over those who wanted a soviet-style council republic. The defeat of the forces of the far Left cleared the way for the establishment of the Weimar Republic.