Claus Kreß is a Professor of International Law and Criminal Law. He is the Director of the Institute of International Peace and Security Law at the University of Cologne. His prior practice was in the German Federal Ministry of Justice. In addition to his scholarly work, comprising more than 200 publications on the law on the use of force, the law of armed conflicts and international criminal law, he has been a member of Germany’s delegations in the negotiations regarding the International Criminal Court as between 1998 and 2017. In 2019, he was appointed Judge ad hoc at the International Court of Justice in the Case of the Application of the Convention on the Prevention and Punishment of the Crime of Genocide (The Gambia v. Myanmar). Since 2021, he has been serving as the Special Adviser to the Prosecutor of the International Criminal Court on the Crime of Aggression.