The jurist und politician Karl Liebknecht (1871–1919), son of the Social Democrat Wilhelm Liebknecht, joined the SPD in 1900 and was on the Berlin city council until 1913. His open criticism of militarism and war repeatedly earned him prison sentences. He entered the Reichstag in 1912, where he represented the extreme left wing of the SPD. In 1916, he and Rosa Luxemburg published the radical Spartacus Letters, which led to his exclusion from the SPD Reichstag fraction. After organizing a peace demonstration in Berlin in 1916, he was sentenced to prison for high treason and lost his Reichstag mandate. A general amnesty was declared in October 1918, leading to Liebknecht's early release. He and Rosa Luxemburg then founded the socialist Spartakus League, distancing themselves from both the SPD and USPD and later becoming founding members of the KPD. On November 9, 1918, he attempted to establish socialism as Germany's new state form by proclaiming a “free socialist republic” two hours after Philipp Scheidemann had proclaimed the “German republic.” Following the Spartacist uprising in January 1919, Liebknecht and Luxemburg were arrested by free corps soldiers, who interrogated, mistreated, and shot them. This photograph shows Liebknecht at a rally in front of the Ministry of the Interior in January 1919.