This report was prepared for the Working Group on the Crime of Aggression at the 8th session of Preparatory Commission, held in September-October 2001. The paper consists of four parts relating to: the Nuremberg tribunal; tribunals establish pursuant to Control Council Law number 10; the Tokyo tribunal; and the United Nations. Annexes contain tables regarding aggression by a State and individual responsibility for crimes against peace. The paper seeks to provide an objective, analytical overview of the history and major developments relating to aggression, both before and after the adoption of the UN Charter.