International criminal law (ICL) is a body of public international law designed to prohibit certain categories of conduct commonly viewed as serious atrocities and to make perpetrators of such conduct criminally accountable for their perpetration. The core crimes under international law are genocide, war crimes, crimes against humanity, and the crime of aggression.
Classical international law governs the relationships, rights, and responsibilities of states. After World War II, the Charter of the International Military Tribunal and the following Nuremberg trial revolutionized international law by applying its prohibitions directly to individuals, in this case the defeated leaders of Nazi Germany, thus inventing international criminal law. After being dormant for decades, international criminal law was revived in the 1990s to address the war crimes in the Yugoslav Wars and the Rwandan genocide, leading to the establishment of a permanent International Criminal Court in 2001.