Article 13 (b) vs Principle of Legality

The crimes of genocide, crimes against humanity, war crimes and aggression have all been crimes within the jurisdiction of at least one of the other international criminal tribunals and courts established prior to the ICC.¹ However, their precise definition as contained in the Rome Statute is in some important respects novel.² Despite the averred intention of the Rome Statute’s drafters to follow customary international law, “drafting the Statute required clarifying and elucidating the precise content of offenses in a way that often moved the ‘law’ of the Statute far beyond existing customary international law understandings.”