The Spartacist League was a left-wing Marxist revolutionary movement organized in Germany during and just after the politically volatile years of World War I, founded by Rosa Luxemburg (nicknamed "Red Rosa") and Karl Liebknecht along with others such as Clara Zetkin. Its greatest period of activity was during the German Revolution of 1918, when it sought to incite a revolution similar to that of the Bolsheviks in Russia by circulating illegal subversive publications, such as the newspaper Spartacus Letters. The League was named after Spartacus, leader of the largest slave rebellion in the history of the Roman Republic. In December of 1918, the League joined the Comintern and renamed itself the Communist Party of Germany (usually abbreviated "KPD", for Kommunistische Partei Deutschlands); on January 1, 1919, the Spartacist League/KPD executed a short-lived Communist revolution in Berlin (against the orders of its leadership), which was easily crushed by nationalist elements.
Both Luxemburg and Liebknecht were prominent members of the left wing faction of the German Social-Democratic Party (SPD). Liebknecht was the son of SPD founder Wilhelm Liebknecht. They moved to found an independent organization after the SPD decided to support the German government's decision to declare war on Russia in 1914, beginning what became World War I. Besides their opposition to what they saw as an imperialist war, they maintained the need for revolutionary methods, in contrast to the leadership of the SPD, who had decided to participate in the parliamentary process.
After the Russian Revolution of 1917, the Spartacists decided to agitate for a similar course, a government based on local workers' councils (soviets) in Germany. Liebknecht and Luxemburg were imprisoned from 1916 until 1918 for their roles in helping to organize a public demonstration in Berlin against German involvement in the war. After the November revolution which overthrew the Kaiser and led to the end of World War I, a period of instability and revolutions began, which would last until 1923. Liebknecht declared a socialist republic in Germany from a balcony of the Kaiser's Berlin City Palace in November of 1918, on the same night that Philipp Scheidemann of the SPD declared the Weimar Republic from the Reichstag.
In December 1918, the Spartakusbund became the German Communist Party (KPD), the German affiliate of the Communist International (Comintern). On January 1, 1919, the KPD attempted to take control of Berlin in what came to be known as the Spartakus uprising. This occurred against the advice of Luxemburg, who argued that an uprising was premature since the Spartakusbund was too weak and not enough of the working class had come over to its side.
The attempted revolution was crushed by the combined forces of the SPD, the remnants of the German Army, and the right-wing paramilitary groups known as the Freikorps, on the orders of chancellor Friedrich Ebert. Luxemburg and Liebknecht, among many others, were killed while held prisoner by the Freikorps, and their bodies dumped in a river. Hundreds of Spartacists were executed in the weeks following the uprising.
The remains of the Spartacist League continued as the Communist Party of Germany (KPD) which retained the League's newspaper, die Rote Fahne (Red Flag), as its publication. After World War II, the Soviet occupation force in East Germany merged the KPD with the Social Democratic Party of Germany in areas under their control, and installed the new Socialist Unity Party as the government of East Germany.