The research here presented is the result of the collaboration of a group of specialists in the history of Europe in the twentieth century, with special dedication to Europeanism from the interwar period, when the new international society arose from the hand of the League of Nations, centred, however, on the so-called Eastern Europe, that is, Central-Eastern, Balkan, and Baltic Europe. The researchers participating in this communal world is part of the Research Project focused, precisely, on the study of the International Society and Europeanism: The Traces of the Other Europes in which the book that concerns us is inscribed: The Eastern countries (Central-Eastern, Balkan and Baltic Europe) and Europeanism: from the interwar period to their aspiration of integration in the Community Europe and a Remembrance project BACHA, focus on the importance of citizens on the political changes of the societies. The work developed is structured in several independent research whose common thread is Europeanism and its influence in a specific part of the Old Continent, Eastern Europe, particularly complex, convulsed, troubled, and even conflictive during practically the whole of the twentieth century.