This article first reviews the historical development of international laws most relevant to women during periods of war or mass violence, particularly international humanitarian law, emphasizing that for centuries, treaties and customary practices overwhelmingly failed to take women and girls, and crimes committed against them, into account. It then examines the treatment of gender-related crimes in the post-World War II trials held in Nuremberg and Tokyo. Finally, this article reviews the most salient gender jurisprudence developed in the Yugoslav and Rwanda Tribunals and by the Statute of the International Criminal Court (ICC).