This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book focuses on Italian economic, social and political development. Regional and economic divisions were only one aspect of the lack of unity of the country. The social bloc which constituted the Italian ruling class was internally as divided as the rest of the country. Northern industrialists and southern landlords did establish a compromise akin to the German alliance between landed and industrial interests. Until the First World War, then, parliament had an essential task: to provide the political terrain on which the different interests which constituted the Italian ruling class could negotiate and find their unity. In 1919 for the first time in Italian history a Catholic party was created, the Partito Popolare, with 100,000 members. The elections of 1919 were fought under proportional representation.