This anthology is about the need for and nature of a convention on crimes against humanity. It uses the Proposed Convention on the Prevention and Punishment of Crimes Against Humanity as an important reference point. 16 authors discuss how such a convention may consolidate the definition of crimes against humanity, and develop measures for their prevention and punishment, decades after the conclusion of the Genocide Convention and Geneva Conventions. The authors include Leila N. Sadat, Eleni Chaitidou, Darryl Robinson, María Luisa Piqué, Travis Weber, Julie Pasch, Rhea Brathwaite, Christen Price, Rita Maxwell, Mary Kate Whalen, Ian Kennedy, SHANG Weiwei, ZHANG Yueyao and Tessa Bolton. It contains a preface by late Judge Hans-Peter Kaul and a foreword by Hans Corell. The book is inspired by the rationale of crimes against humanity to protect against the most serious violations of fundamental individual rights, and its realization especially through domestic mechanisms. Such consciousness calls upon appropriate definition and use of contexual elements of the crime, effective jurisdiction for prevention and prosecution, and robust inter-State co-operation. The book considers individual State experiences in combating crimes against humanity. It underlines the importance of avoiding that the process to develop a new convention waters down the law of crimes against humanity or causes further polarisation between States in the area of international criminal law. It suggests that the scope of the obligation to prevent crimes against humanity will become a decisive question.