Which entity is this text about?

Rosa Luxemburg  (also Rozalia Luxenburg; Polish: Roza Luksemburg; 5 March 1871 - 15 January 1919) was a Polish Marxist theorist, philosopher, economist, anti-war activist, and revolutionary socialist who became a naturalized German citizen at the age of 28. She was, successively, a member of the Social Democracy of the Kingdom of Poland and Lithuania (SDKPiL), the Social Democratic Party of Germany (SPD), the Independent Social Democratic Party (USPD), and the Communist Party of Germany (KPD). In 1915, after the SPD supported German involvement in World War I, she 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 was born on 5 March 1871, in Zamosc. She and her family were Polish Jews living in Russian-controlled Poland. She was the fifth and youngest child of timber trader Eliasz Luxemburg and Line Lowenstein. Luxemburg later stated that her father imparted an interest in liberal ideas in her, while her mother was religious and well read with books kept at home. The family spoke German and Polish, and Luxemburg also learned Russian. The family moved to Warsaw in 1873. After being bedridden with a hip ailment at the age of five, she was left with a permanent limp.  Starting in 1880, Luxemburg attended a gymnasium. From 1886, she belonged to the Polish left-wing Proletariat Party (founded in 1882, anticipating the Russian parties by 20 years). She began political activities by organizing a general strike; as a result, four of the Proletariat Party leaders were put to death and the party was disbanded, though the remaining members, including Luxemburg, kept meeting in secret. In 1887, she passed her Matura (secondary school graduation) examinations. After fleeing to Switzerland to escape detention in 1889, she attended the University of Zurich (as did the socialists Anatoly Lunacharsky and Leo Jogiches), where she studied philosophy, history, politics, economics, and mathematics. She specialized in Staatswissenschaft (government science), the Middle Ages, and economic and stock exchange crises.  Her doctoral dissertation, "The Industrial Development of Poland" (Die Industrielle Entwicklung Polens), was officially presented in the spring of 1897 at the University of Zurich, which awarded her a Doctor of Law degree. Her dissertation was published by Duncker and Humblot in Leipzig in 1898. She was an oddity in Zurich as she was one of the very few women with a doctorate. She plunged immediately into the politics of international Marxism, following in the footsteps of Georgi Plekhanov and Pavel Axelrod.  In 1893, with Leo Jogiches and Julian Marchlewski (alias Julius Karski), Luxemburg founded the newspaper Sprawa Robotnicza ("The Workers' Cause"), which opposed the nationalist policies of the Polish Socialist Party. Luxemburg believed that an independent Poland could arise and exist only through socialist revolutions in Germany, Austria, and Russia. She maintained that the struggle should be against capitalism, not just for Polish independence. Her position of denying a national right of self-determination under socialism provoked a philosophic disagreement with Vladimir Lenin. She and Leo Jogiches co-founded the Social Democracy of the Kingdom of Poland and Lithuania (SDKPiL) party, after merging Congress Poland's and Lithuania's social democratic organizations. Despite living in Germany for most of her adult life, Luxemburg was the principal theoretician of the Social Democracy of the Kingdom of Poland (SDKP, later the SDKPiL), and led the party in a partnership with Jogiches, its principal organizer.
Rosa Luxemburg