This book describes the present status and the history of the International Union of Psychological Science (IUPsyS) - the most representative international psychological body. The IUPsyS includes national psychological associations from 66 countries, with more joining every year, and it has formal relations with the United Nations, UNESCO, the World Health Organization, the International Council for Science, and the International Social Science Council. Many well known psychologists have played important roles in this international organization, and the text and many photographs bring the story to life.