This is a history of political ideologies during the period from the First World War to the collapse of the Soviet Union, famously described by Eric Hobsbawm as 'The Age of Extremes'. By introducing the key ideologies of the twentieth-century: liberalism, conservatism, communism and fascism, and considering them in in relation to each other, Willie Thompson shows how these philosophies often emerged from a common root or merged into a common future,...