Marx’s influence, which has extended beyond communist societies, can be compared to that of major religious figures like Jesus or Muhammad. The lives of hundreds of millions of people were transformed, for better or for worse, by Marx’s legacy. ‘A life and its legacy’ outlines Marx’s life, marriage, and family; his early intellectual career; his friendship and collaboration with Friedrich Engels; and describes the slow-burning impact of his key publication, Capital. His ideas transformed the study of history and sociology, and profoundly affected philosophy, literature, and the arts. In this sense of the term we are all Marxists now. What were the ideas that had such far-reaching effects?