The crimes known as the core international crimes, such as crimes against humanity and genocide, are imprescriptible, i.e., no time bars apply for their prosecution. Ever since the atrocities of the Second World War, the notion of the imprescriptible has become synonymous with the law’s dealing with the most heinous criminal acts. Not only lawyers, also philosophers have reflected on the theme and related concepts such as forgiveness and revenge. In criminal law, imprescriptible crimes form an exception. Normally, alleged criminal behaviour is subject to a so-called statute of limitations. These are ‘statute(s) providing for a timeframe within which criminal proceedings must be instituted. Statutes of limitation provide for a non-exculpatory defense to a criminal defendant. Accordingly, even if the accused is allegedly culpable, a statute of limitations will bar prosecution if an action is not timely commenced. Statutes of limitation appear not only in criminal law, but in international, civil, administrative, or tax law as well.’ 2 These statutes tend to ‘limit two types of action: limitations to criminal actions and limitations to the enforcement of sentences.’ 3 In other words, the passage of time affects the question whether or not a crime can be prosecuted. Time thus co-determines whether something is a matter of law. As said, the absence of such a statute of limitations is in contradiction with the normal situation in criminal law, in which crimes are (basically) all subjected to a statute of limitations. The especially shocking nature of international crimes is usually regarded as the justification for this exception.