Rosa Luxemburg was the youngest of five children born to a lower middle-class Jewish family living in the Polish region of Russia. She became interested in politics as a young girl. At 16, she graduated at the top of her class at gymnasium in Warsaw, but was denied the gold medal because of "an oppositional attitude toward the authorities." In 1889, Rosa went to Zurich University to study law and political economy. In Switzerland she met numerous political exiles, including Leo Jogiches, with whom she began a long romantic relationship; though a few years later, she married Gustav Lübeck to obtain German citizenship. She settled in Berlin, where she joined the Social Democratic Party (SPD). She was active in revolutionary politics in Poland, Lithuania, France, and Germany and was imprisoned on several occasions for this and for opposing World War I. A leading Marxist theorist, she published numerous pamphlets and books including The Accumulation of Capital (1913). She and Karl Liebknecht co-founded the Spartakusbund -- Spartacus League or Spartacists -- which eventually became the German Communist Party. During the German Revolution of 1918-1919, Rosa founded Die Rote Fahne (The Red Flag), the newspaper of the Spartacist movement. When the revolt was crushed by the government and the Freikorps (right-wing paramilitary groups), Rosa Luxemburg, Liebknecht, and some of their supporters were captured and murdered while in police custody.