Rosa Luxemburg (right) and Clara Zetkin, 1910
Released from her Warsaw prison, she taught at the Social Democratic Party school in Berlin (1907-14), where she wrote Die Akkumulation des Kapitals (1913; The Accumulation of Capital). In this analysis, she described imperialism as the result of a dynamic capitalism's expansion into underdeveloped areas of the world. It was during this time also that she began to agitate for mass actions and broke completely with the established Social Democratic party leadership of August Bebel and Kautsky, who disagreed with her incessant drive toward proletarian radicalization.
The Social Democratic Party backed the German government at the outbreak of World War I, but Rosa Luxemburg immediately went into opposition. In an alliance with Karl Liebknecht and other like-minded radicals, she formed the Spartakusbund, or Spartacus League, which was dedicated to ending the war through revolution and the establishment of a proletarian government. The organization's theoretical basis was Luxemburg's pamphlet Die Krise der Sozialdemokratie (1916; The Crisis in the German Social Democracy), written in prison under the pseudonym Junius. In this work she agreed with Lenin in advocating the overthrow of the existing regime and the formation of a new International strong enough to prevent a renewed outbreak of mass slaughter. The actual influence of the Spartacus group during the war, however, remained small.
Released from prison by the German revolution (November 1918), Luxemburg and Liebknecht immediately began agitation to force the new order to the left. They exercised considerable influence on the public and were a contributing factor in a number of armed clashes in Berlin. Like the Bolsheviks, Luxemburg and Liebknecht demanded political power for the workers' and soldiers' soviets but were frustrated by the conservative Socialist establishment and the army. In late December 1918, they became founders of the German Communist Party, but Luxemburg attempted to limit Bolshevik influence in this new organization. In fact, her Die russische Revolution (1922; The Russian Revolution) chastised Lenin's party on its agrarian and national self-determination stands and its dictatorial and terrorist methods. Luxemburg always remained a believer in democracy as opposed to Lenin's democratic centralism. She was never able, however, to exercise a decisive influence on the new party, for she and Liebknecht were assassinated in 1919 by reactionary troops.
"Luxemburg, Rosa" Encyclopædia Britannica Online.