This volume provides a record of the proceedings of the fifth annual meeting of international prosecutors at Chautauqua Institution from August 28-30, 2011. The theme of these Dialogs was “Widespread and Systematic! – Crimes Against Humanity in the Shadow of Modern International Criminal Law.” The international prosecutors, academics, practitioners, and members of the public discussed the evolution of this crime and challenges in its prosecution. The Crimes Against Humanity Initiative, an initiative working towards the development and signing of an International Convention on the Prevention and Punishment of Crimes Against Humanity, is also presented, and its Proposed Convention is included in this volume. The volume also contains the prosecutors’ updates regarding the activities of their respective courts and tribunals during the past year.