The issue of conflict-related sexual violence against women has been marginalized for centuries, since rape was considered a negligible side-effect of war. This perception only changed in the 1990ies, when the Yugoslav Wars and the Rwandan genocide revealed massive sexual atrocities that were often consciously employed as part of a military tactic. Since then, a rapid development concerning the prohibition of sexual violence can be observed in international law. This thesis has a twofold research purpose: Firstly, the protection against sexual violence is examined in International Humanitarian Law and International Criminal Law. Secondly, a currently still contentious aspect of this prohibition is specifically addressed ? the lack of a settled definition of rape as an international crime.While an explicit prohibition of rape is already laid down in the Geneva Conventions and their Additional Protocols, the scope of protection against sexual violence has been significantly expanded by the jurisprudence of the international criminal tribunals. Both the ICTY and the ICTR have prosecuted sexual violence under every category of international crimes contained in their statutes, i.e. as crimes against humanity, war crimes and genocide.In addition, the tribunals can be credited with developing the first international definitions of rape, since there was no definition of the crime in international law at the time of their establishment. So far, three principal definitions have emerged from the tribunals? case flow, which were contained in the Akayesu Judgment, the Furund?ija Judgment and the Kunarac et al. Judgment. Moreover, there is now a written definition of rape laid down in the Elements of Crimes of the International Criminal Court. This thesis analyzes each of these definitions in order to evaluate which of them is to be preferred. Lastly, Chapter V (Conclusion) includes a proposal for a new, alternative wording of the definition of rape as an international crime.