Antonio Gramsci is today the most quoted Italian author worldwide after Dante. Arrested in 1926 as a political opponent of the fascist regime, he wrote a work of over two thousand printed pages while in prison. These so-called Prison Notebooks are among the most interesting writings on history and literature, politics, philosophy, religion, and emancipation produced in the 20th century. The present introduction focuses on them but also provides insights into the early work and biography of the Sardinian thinker, politician, and co-founder of the Communist Party. Additionally, the volume offers perspectives on academic fields such as Cultural Studies and International Political Economy, for which Gramsci has become an inspiration and a modern classic.