The Spartacist uprising, also known as the January uprising, was an armed uprising that took place in Berlin from 5 to 12 January 1919. It occurred in connection with the November Revolution that broke out following Germany's defeat in World War I. The uprising was primarily a power struggle between the Social Democratic Party of Germany (SPD) led by Friedrich Ebert, which favored a social democracy, and the Communist Party of Germany (KPD), led by Karl Liebknecht and Rosa Luxemburg, which wanted to set up a council republic similar to the one established by the Bolsheviks in Russia. In 1914 Liebknecht and Luxemburg had founded the Marxist Spartacus League, which gave the uprising its popular name.

The Weimar Republic, officially known as the German Reich, was a historical period of Germany from 9 November 1918 to 23 March 1933, during which it was a constitutional federal republic for the first time in history; hence it is also referred to, and unofficially proclaimed itself, as the German Republic. The period's informal name is derived from the city of Weimar, which hosted the constituent assembly that established its government. In English, the republic was usually simply called "Germany", with "Weimar Republic" not commonly used until the 1930s.