After the SPD supported German involvement in World War I in 1915, Luxemburg and Karl Liebknecht co-founded the anti-war Spartacus League ("Spartakusbund") which eventually became the KPD. During the November Revolution, she co-founded the newspaper "Die Rote Fahne" ("The Red Flag"), the central organ of the Spartacist movement. Luxemburg considered the Spartacist uprising of January 1919 a blunder, but supported the attempted overthrow of the government and rejected any attempt at a negotiated solution. Friedrich Ebert's majority SPD government crushed the revolt and the "Spartakusbund" by sending in the "Freikorps," government-sponsored paramilitary groups consisting mostly of World War I veterans. "Freikorps" troops captured and summarily executed Luxemburg and Liebknecht during the rebellion.