Genocide is the most extreme form of violence: an act that seeks the total destruction of a human group on the grounds of identity, origin, religion, or culture. However, in a world saturated with information, this concept has been distorted, being used to describe events that do not always correspond to its true meaning. In The Age of Genocide, the author, an ICADE professor and expert in international relations, offers an enlightening overview that clearly and precisely distinguishes between genocide, crimes against humanity, war crimes, and the crime of aggression, explaining their characteristics, their impact, and their place within international law. From the Holocaust and the persecution of the Armenian people to more recent cases, such as Rwanda, Srebrenica, Darfur, the Rohingya, the Yazidi people, Ukraine, and Palestine, this book combines historical narrative with the evolution of the normative and judicial architecture created by the international community to understand the roots and consequences of these crimes, as well as the mechanisms for punishing them. The work also examines the major milestones in international justice, from the Nuremberg Trials to the creation and functioning of the International Criminal Court (ICC) and the role of the International Court of Justice (ICJ). Through this analysis, it reveals the complex struggle against impunity and the dilemmas of a global world that seeks to protect fundamental human rights in the face of the political interests of the great powers and the practice of unacceptable double standards. The history of genocide is not only a chronicle of the horrors of the past, but also an essential guide to understanding current conflicts and the challenges of global justice. An indispensable text for lawyers, journalists, students, and any reader committed to the defense of human rights and the prevention of new crimes. Understanding the past is not just an exercise in memory: it is the key to preventing history from repeating itself.