Die Rote Fahne was a German newspaper originally founded in 1876 by Socialist Worker's Party leader Wilhelm Hasselmann, and which has been since published on and off, at times underground, by German Socialists and Communists. Karl Liebknecht and Rosa Luxemburg famously published it in 1918 as organ of the Spartacus League.

Karl Paul August Friedrich Liebknecht was a German socialist and anti-militarist. A member of the Social Democratic Party of Germany (SPD) beginning in 1900, he was one of its deputies in the Reichstag from 1912 to 1916, where he represented the left-revolutionary wing of the party. In 1916 he was expelled from the SPD's parliamentary group for his opposition to the Burgfriedenspolitik, the political truce between all parties in the Reichstag while the war lasted. He twice spent time in prison, first for writing an anti-militarism pamphlet in 1907 and then for his role in a 1916 antiwar demonstration. He was released from the second under a general amnesty three weeks before the end of the First World War.