Rosa Luxemburg (Polish: [ˈruʐa ˈluksɛmburk]; German: [ˈʁoːza ˈlʊksəmbʊʁk]; Polish: Róża Luksemburg or Rozalia Luksenburg; 5 March 1871 – 15 January 1919) was a Polish and naturalised-German revolutionary socialist, Marxist philosopher and anti-war activist. Successively, she was a member of the Proletariat party, the Social Democracy of the Kingdom of Poland and Lithuania (SDKPiL), the Social Democratic Party of Germany (SPD), the Independent Social Democratic Party (USPD), the Spartacus League (Spartakusbund), and the Communist Party of Germany (KPD). Born and raised in an assimilated Jewish family in Poland, she became a German citizen in 1897.