For many arms dealers are evil. They are the root cause for gun violence, terrorism and wars. In both public and academic debates, arms dealers are considered immoral as they profit from conflict, due to their key position in the international arms trading business. Nevertheless, there seems to be little to no interest in the personal lives of arms dealers. By having written a criminological biography of a legal arms dealer, Constantine (his pseudonymised name), Yarin Eski provides an in-depth understanding of an arms dealer. Seen through Constantine’s own eyes, the biography gives a deep insider-view of the arms trade, put in a wider socio-cultural context. In doing so, this book discusses Constantine’s childhood, family life, career choices and being an arms dealer. The biography will be methodologically embedded and advancing biographical writing in the field of criminology, while enriching the fields of ethnography, sociology, (critical) security studies, policing studies, war studies and international politics with a unique insight from within.