Revolutionary Marxist activist Rosa Luxemburg (1871–1919) has long been a major inspiration for activists on the left. But what can we learn from looking closely at her life today? Jon Nixon answers that question here, offering a clear, concise account of Luxemburg’s biography and thought and setting it in relation to contemporary economic, political, and social debates. Nixon presents Luxemburg as not only an activist, but also as a major political theorist, showing how her thinking about global capitalism, state militarism, and other subjects can still be applied today, with powerful effects. By establishing a rich and distinctive account of Luxemburg, Nixon makes a compelling argument for the continuing relevance of her struggle for democratic renewal.