This article argues that instead of using inconsistent and often tautological ad hoc definitions from social sciences and the humanities, the legal notion of genocide as it emerges from the Genocide Convention and the jurisprudence of international criminal tribunals should also be applied to historical atrocities. This helps to prevent the inflationary use of the term ‘genocide’, whose inevitable consequence is that this term is voided of any meaning. Using instead the legal concept makes it possible to disentangle genocidal from non-genocidal violence and to prevent this notion from becoming obsolete. Three examples from German colonial history in Africa illustrate the need for such an approach. Key words: genocide, war crimes, German, Africa, Schutztruppen, colonial, international criminal tribunals