This seminar is an introductory survey of the substantive and procedural aspects of international criminal law, a new and evolving area of law that has gained in prominence in the past decade. The course starts with an overview of fundamentals, focusing on the notion of international crimes and their historical evolution, as well as the general features and sources of international criminal law. The second part of the seminar analyzes the substantive law, especially the definitions and subjective and objective elements of genocide, crimes against humanity and war crimes. The discussion will take place within the context of a comparative evaluation of the main international judicial mechanisms developed after World War II to prosecute these crimes. Particular attention is paid to the International Military Tribunal at Nuremberg, the ad hoc United Nations International Criminal Tribunals for the former Yugoslavia and Rwanda, the Special Court for Sierra Leone and the permanent International Criminal Court. In the final part, we examine the fair trial rights and the limited defenses and immunities available to alleged perpetrators of international crimes. A key question students will be expected to engage throughout is whether, and if so to what extent, individual criminal prosecution is a legitimate and effective tool to address mass human rights violations during or after conflict.