The categorization of the crimes and the constitution of the court represented a juridical advance that would be followed afterward by the United Nations for the development of an international jurisprudence in matters of war crimes , crimes against humanity , and wars of aggression , and led to the creation of the International Criminal Court . For the first time in international law , the Nuremberg indictments also mention genocide ( count three , war crimes : " the extermination of racial and national groups , against the civilian populations of certain occupied territories in order to destroy particular races and classes of people and national , racial , or religious groups , particularly Jews , Poles , and Gypsies and others . " ) A precedent for trying those accused of war crimes had been set at the end of World War I in the Leipzig War Crimes Trials held in May to July 1921 before the '' Reichsgericht '' ( German Supreme Court ) in Leipzig , although these had been on a very limited scale and largely regarded as ineffectual . At the beginning of 1940 , the Polish government-in-exile asked the British and French governments to condemn the German invasion of their country . The British initially declined to do so ; however , in April 1940 , a joint declaration was issued by the British , French and Polish . Relatively bland because of Anglo-French reservations , it proclaimed the trio 's '' " desire to make a formal and public protest to the conscience of the world against the action of the German government whom they must hold responsible for these crimes which can not remain unpunished . " '' Three-and-a-half years later , the stated intention to punish the Germans was much more trenchant . On 1 November 1943 , the Soviet Union , the United Kingdom and the United States published their " Declaration on German Atrocities in Occupied Europe " , which gave a " full warning " that , when the Nazis were defeated , the Allies would " pursue them to the uttermost ends of the earth ... in order that justice may be done . ... The above declaration is without prejudice to the case of the major war criminals whose offences have no particular geographical location and who will be punished by a joint decision of the Government of the Allies . " This intention by the Allies to dispense justice was reiterated at the Yalta Conference and at Potsdam in 1945
Potsdam
Potsdam Conference
Nuremberg trials