This introduction presents an overview of key concepts discussed in the subsequent chapters of the book. The book deals with the first half of the century, during the period of hope and despair. It focuses on the destruction of the old European empires at the close of the First World War. The book covers the development of national self-determination, fascism and anti-Semitism in Europe, the creation of international socialist institutions and the British mandate of Palestine. It is about the issues which arise from nation-building; territory, criteria for including and excluding people, ethnicity, the rights of ethnic minorities, class and the representation of workers in civil government, personal identities. The Labour Heritage conference marked the founding of the state of Israel as an historical event, but this in no way meant that participants necessarily took a Zionist stance. Indeed, it was the forum for lively debate on the politics and historiography of Zionism.