This book represents the work of a community of criminal lawyers connected to the University of Oxford and the Max Planck Institute for Foreign and International Criminal Law in Freiburg, and there are many people who deserve thanks for it coming to life on the page. While the editors were lucky to work with such talented and diligent authors, they were particularly lucky to have the sage guidance of Ulrich Sieber, Director at the Max Planck Institute. From the English side, Lucia Zedner, Rebecca Williams and Grant Lamond also helped in numerous ways, from logistics to detailed discussions of the finer points making a book about criminal law. The funding for the two workshops came from the Research Support Fund of the Faculty of Law, University of Oxford, and from the Max Planck Institute, to whom all participants in the project are very grateful. The project benefitted greatly from the assistance of Anna Riddell-Roberts in preparing the texts, and in bringing the book from ideas through to the hands of readers, the wonderful team at Intersentia, with Ann-Christin Maak-Scherpe and Rebecca Moffat deserving particular thanks.