This volume describes the various movements and parties across all six continents that wanted social change through state transformation. It begins with a reconstruction of social democracy’s trajectories from the 1870s until the present. The evolution of socialism on different continents is reconstructed through a number of national case studies. Experiments at a sub-national level are also explored (for example, municipal socialism), as are the varying experiences of international umbrella organisations. The next part focuses on divergent socialist experiments and ideologies in several parts of the world, including South Asia, Africa, the Arab world, Brazil, Venezuela and Israel, followed by an overview of ‘independent’ socialist movements, including left-socialist parties of the 1930s, and the post-war period, and the global New Left since its beginnings in the 1950s.