This work is a comprehensive text in the field of psychohistory that presents both the theory and the practice of this interdisciplinary field. The presentation of psychoanalytic theory in this work includes the fundamental contributions made by Freud as well as the post-Freudian developments. Another unique feature of this work, because psychohistory is so controversial, is that the pros and cons are presented, thereby putting the field in better relief. This work accentuates how psychohistory differs from traditional history, and how psychohistory is more insightful in the study of the individual, the family, and the group. In sum, 'Psychohistory-Theory and Practice' demonstrates how psychohistory is transforming the study of history and why psychohistory is so promising for our understanding of mankind.