Rosa Luxemburg (/ˈlʌksəmbɜːrɡ/ LUK-səm-burg; Polish: Róża Luksemburg [ˈruʐa ˈluksɛmburk] ; German: [ˈʁoːza ˈlʊksm̩bʊʁk] ; 5 March 1871 – 15 January 1919) was a Polish and naturalised-German Marxist theorist and revolutionary. She was a leading theorist of the Social Democratic Party of Germany (SPD) and later co-founded the anti-war Spartacus League, which evolved into the Communist Party of Germany (KPD). An influential member of the international socialist movement, she is remembered for her writings on imperialism and revolution, and as a champion of socialist democracy who famously stated, "Freedom is always and exclusively freedom for the one who thinks differently."
Born and raised in Russian-ruled Poland to a secular Jewish family, Luxemburg became active in revolutionary politics in her youth. She co-founded the Social Democracy of the Kingdom of Poland and Lithuania (SDKPiL), a party that rejected Polish nationalism in favour of an international class struggle. After moving to Germany in 1898, she became the foremost voice of the SPD's revolutionary wing. In her 1900 pamphlet Social Reform or Revolution?, she defended the necessity of revolution against the reformist theories of Eduard Bernstein, arguing that the struggle for reforms was a means to an end, not an end in itself. Inspired by the 1905 Russian Revolution, she developed a theory of the mass strike as the proletariat's most important revolutionary tool, emphasizing the spontaneous creativity of the working class.
