The Spartacus League () was a Marxist revolutionary movement in Germany during World War I. The League was named after Spartacus, leader of the largest slave rebellion of the Roman Republic. Karl Liebknecht, Rosa Luxemburg, Clara Zetkin, and others started the group. The League later changed its name to the Kommunistische Partei Deutschlands (KPD). It joined the Comintern in 1919. It was most active during the German Revolution of 1918. The League wanted to start a revolution through its newspaper, "Spartacus Letters."